aklow labs·chess

SonnetvsHaiku

0-1 · checkmate · 84 Halbzuege · $3.6612 Kosten · 1.488 in / 670.104 out · Langfuse-Trace ↗

Ply 84 / 84

Halbzuege (84)

  1. 1.e4Sonnet606 tok · $0.0090 · 35786ms
    • 1. Observe0 tok · 0ms

      Halbzug 1, Weiss am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 20. Criticality: 0.30.

      • material-counter0ms
    • 2. Recall Position0 tok · 9ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search9ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan190 tok · 16308ms · claude-sonnet-4-6 · $0.0028

      Phase: opening. Establish central control with a pawn on e4 or d4, then develop knights (f3, c3) before bishops, and prepare to castle kingside within 5-6 moves. Build a solid classical pawn center, complete development …

      • llm.plan16307ms · $0.0028
      full reasoning
      Phase: opening. Establish central control with a pawn on e4 or d4, then develop knights (f3, c3) before bishops, and prepare to castle kingside within 5-6 moves. Build a solid classical pawn center, complete development with king safety via short castling, then exploit any structural weaknesses the opponent creates. Critical: No opponent threats yet — full freedom of choice; Must not develop queen early per memory heuristic [OPENING queen late]; Central control is the priority per [OPENING central control] — e4 or d4 pawn immediately.
    • 6. Candidates231 tok · 9158ms · claude-sonnet-4-6 · $0.0034

      Candidates: e4 (Central control priority: occupies e4, opens lines for bishop and queen, classical king-pawn opening.) | d4 (Central control heuristic: d4 fights for center immediately, leads to solid queen-pawn structur…

      • chess.js.legal_moves0ms
      • llm.candidates9148ms · $0.0034
      full reasoning
      Candidates: e4 (Central control priority: occupies e4, opens lines for bishop and queen, classical king-pawn opening.) | d4 (Central control heuristic: d4 fights for center immediately, leads to solid queen-pawn structures.) | Nf3 (Develop knight before bishops, controls e5/d4, flexible — fits any pawn center plan.)
    • 7. Verify0 tok · 2ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect185 tok · 10084ms · claude-sonnet-4-6 · $0.0027

      Final pick: e4 — Central control heuristic demands immediate pawn presence. e4 grabs the center, opens diagonals for Bc4 and the queen, and commits to a classical king-pawn structure with maximum space.. Rejected: d2d4, …

      • llm.reflect10083ms · $0.0027
      full reasoning
      Final pick: e4 — Central control heuristic demands immediate pawn presence. e4 grabs the center, opens diagonals for Bc4 and the queen, and commits to a classical king-pawn structure with maximum space.. Rejected: d2d4, g1f3.
    • 9. Commit0 tok · 0ms

      Commit e4 (e2e4).

  2. 2...d5Haiku5.561 tok · $0.0277 · 70301ms
    • 1. Observe0 tok · 0ms

      Halbzug 2, Schwarz am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 20. Criticality: 0.30.

      • material-counter0ms
    • 2. Recall Position0 tok · 16ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search16ms
    • 3. Recall Opponent0 tok · 11ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search11ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan2053 tok · 24745ms · claude-haiku-4-5 · $0.0102

      Phase: opening. Establish a solid center response to e4, develop the knight to f6 and prepare a central counter (d5 or c5) within 3-5 moves, avoiding any early queen moves. Achieve central equality through direct or indi…

      • llm.plan24745ms · $0.0102
      full reasoning
      Phase: opening. Establish a solid center response to e4, develop the knight to f6 and prepare a central counter (d5 or c5) within 3-5 moves, avoiding any early queen moves. Achieve central equality through direct or indirect contest, safely develop pieces, and reach a balanced middlegame ready for both sides to maneuver. Critical: White's e4 pawn controls crucial center squares; Black must challenge it immediately via d5, c5, or solidify with e5; Black's first two piece moves must be knights (especially the one contesting e4); Laeufer development comes later; White threatens d4 next move, which strengthens the center further if uncontested; Queen stays home until move 6-7; early deployment loses tempo against developing moves.
    • 6. Candidates1978 tok · 23258ms · claude-haiku-4-5 · $0.0099

      Candidates: d5 (Directly challenges White's e4, forces immediate center decision, seizes initiative.) | e5 (Establishes immediate parity, prepares flexible knight development, maintains central presence.) | Nc6 (Develops…

      • chess.js.legal_moves0ms
      • llm.candidates23257ms · $0.0099
      full reasoning
      Candidates: d5 (Directly challenges White's e4, forces immediate center decision, seizes initiative.) | e5 (Establishes immediate parity, prepares flexible knight development, maintains central presence.) | Nc6 (Develops piece, supports d5/e5 advances, controls d4 and e5 squares.)
    • 7. Verify0 tok · 2ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect1530 tok · 22252ms · claude-haiku-4-5 · $0.0076

      Final pick: d5 — Immediately contests White's e4, forces central decision this move. If 2.exd5 Qxd5 develops with tempo; if White avoids capture, Black trades favorably. Sharpest reply.. Rejected: e7e5, b8c6.

      • llm.reflect22252ms · $0.0076
    • 9. Commit0 tok · 0ms

      Commit d5 (d7d5).

  3. 3.d4Sonnet688 tok · $0.0102 · 31914ms
    • 1. Observe0 tok · 0ms

      Halbzug 3, Weiss am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 31. Criticality: 0.30.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 4ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search4ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan266 tok · 11412ms · claude-sonnet-4-6 · $0.0040

      Phase: opening. Play d4 to establish a full classical pawn center (e4+d4), then develop Nf3 and Nc3, followed by kingside castling within moves 5-6. Build an imposing pawn center, complete development with king safety vi…

      • llm.plan11412ms · $0.0040
      full reasoning
      Phase: opening. Play d4 to establish a full classical pawn center (e4+d4), then develop Nf3 and Nc3, followed by kingside castling within moves 5-6. Build an imposing pawn center, complete development with king safety via short castling, then convert space advantage into a winning middlegame. Critical: Opponent played 1...d5 — central tension exists; d4 resolves it favorably for White; Per [OPENING central control]: e4+d4 center is the priority — d4 now secures both squares; Per [OPENING knights before bishops]: Nf3 next, attacking d5 and preparing castle — no early queen; No immediate opponent threats; full freedom to execute classical development plan; Own weakness: e4 pawn undefended — d4 or Nf3 must address this promptly.
    • 6. Candidates246 tok · 8614ms · claude-sonnet-4-6 · $0.0037

      Candidates: d4 (Establishes full e4+d4 center per [OPENING central control] heuristic; defends e4 and gains space.) | Nf3 (Per [OPENING knights before bishops]: attacks d5, defends e4 indirectly, prepares kingside castli…

      • chess.js.legal_moves0ms
      • llm.candidates8612ms · $0.0037
      full reasoning
      Candidates: d4 (Establishes full e4+d4 center per [OPENING central control] heuristic; defends e4 and gains space.) | Nf3 (Per [OPENING knights before bishops]: attacks d5, defends e4 indirectly, prepares kingside castling.) | exd5 (Resolves central tension immediately, gains tempo; simplifies but cedes d4 square long-term.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect176 tok · 11856ms · claude-sonnet-4-6 · $0.0026

      Final pick: d4 — Per [OPENING central control]: establishes the full e4+d4 pawn center, defends e4, and gains maximum space. Forces Black to react to the tension rather than letting me resolve it prematurely.. Rejected: …

      • llm.reflect11856ms · $0.0026
      full reasoning
      Final pick: d4 — Per [OPENING central control]: establishes the full e4+d4 pawn center, defends e4, and gains maximum space. Forces Black to react to the tension rather than letting me resolve it prematurely.. Rejected: g1f3, e4d5.
    • 9. Commit0 tok · 0ms

      Commit d4 (d2d4).

  4. 4...Nf6Haiku8.811 tok · $0.0439 · 95099ms
    • 1. Observe0 tok · 0ms

      Halbzug 4, Schwarz am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 28. Criticality: 0.30.

      • material-counter0ms
    • 2. Recall Position0 tok · 16ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search16ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan2106 tok · 26302ms · claude-haiku-4-5 · $0.0105

      Phase: opening. Deploy Nf6 to challenge e4 and develop with tempo. Prepare d5 support via c5 or maintain tension. Keep White's pawns under piece pressure while completing knight development by move 5. Resolve the center …

      • llm.plan26302ms · $0.0105
      full reasoning
      Phase: opening. Deploy Nf6 to challenge e4 and develop with tempo. Prepare d5 support via c5 or maintain tension. Keep White's pawns under piece pressure while completing knight development by move 5. Resolve the center equilibrium through piece coordination rather than premature pawn exchanges, pivot to a balanced middlegame where Black's pieces counter White's spatial advantage. Critical: e4 attacked by d5 but defended by d4—White's center is strong but pressureable; Nf6 is the forcing move: develops a piece + attacks e4 simultaneously; c5 or exd4 are the main center-resolution plans after Nf6; Queen stays home; no early moves before move 6. Castle kingside by move 8 to ensure king safety.
    • 6. Candidates2654 tok · 27768ms · claude-haiku-4-5 · $0.0132

      Candidates: Nf6 (Develops with tempo, attacks e4, forces White to commit. Forcing move.) | c5 (Challenges d4, maintains tension, supports d5 and develops queenside.) | dxe4 (Simplifies center, opens lines, reduces White'…

      • chess.js.legal_moves0ms
      • llm.candidates27762ms · $0.0132
      full reasoning
      Candidates: Nf6 (Develops with tempo, attacks e4, forces White to commit. Forcing move.) | c5 (Challenges d4, maintains tension, supports d5 and develops queenside.) | dxe4 (Simplifies center, opens lines, reduces White's space advantage cleanly.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4051 tok · 40986ms · claude-haiku-4-5 · $0.0202

      Final pick: Nf6 — Develops knight with tempo, simultaneously attacks both e4 and d4. Forcing move that pressures White's center and maintains flexibility for c5 or exd4 resolution.. Rejected: c7c5, d5e4.

      • llm.reflect40986ms · $0.0202
    • 9. Commit0 tok · 0ms

      Commit Nf6 (g8f6).

  5. 5.Nf3Sonnet752 tok · $0.0112 · 29873ms
    • 1. Observe0 tok · 0ms

      Halbzug 5, Weiss am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 38. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan299 tok · 11640ms · claude-sonnet-4-6 · $0.0044

      Phase: opening. Develop Nf3 attacking d5, then Nc3 supporting the center, followed by Bc4 or Bf4, and castle kingside by move 7-8. Maintain the e4+d4 pawn center while completing development before any pawn exchanges. Co…

      • llm.plan11640ms · $0.0044
      full reasoning
      Phase: opening. Develop Nf3 attacking d5, then Nc3 supporting the center, followed by Bc4 or Bf4, and castle kingside by move 7-8. Maintain the e4+d4 pawn center while completing development before any pawn exchanges. Convert the classical pawn center advantage into a space-dominant middlegame where Black's pieces are cramped and White can attack on either wing after castling. Critical: Per [OPENING knights before bishops]: Nf3 is the principled next move — attacks d5, prepares castling, avoids premature queen development; Per [OPENING central control]: e4+d4 center is intact; must not allow Black to undermine it with ...dxe4 without immediate recapture; Black's Nf6 eyes e4 — if White plays passively, ...dxe4 followed by knight activity could equalize; Nf3 counters this directly; No immediate threats from Black; position is stable but tempo matters in the opening.
    • 6. Candidates251 tok · 9365ms · claude-sonnet-4-6 · $0.0037

      Candidates: Nf3 (Knights before bishops principle: attacks d5, supports e4+d4 center, prepares castling. Counters Black's Nf6 eyeing e4.) | Nc3 (Develops knight to best square, supports d4 pawn, maintains central control…

      • chess.js.legal_moves0ms
      • llm.candidates9363ms · $0.0037
      full reasoning
      Candidates: Nf3 (Knights before bishops principle: attacks d5, supports e4+d4 center, prepares castling. Counters Black's Nf6 eyeing e4.) | Nc3 (Develops knight to best square, supports d4 pawn, maintains central control heuristic without premature pawn exchanges.) | Bc4 (Classical development targeting f7, eyes the central diagonal. Fits opening principle of completing minor piece development before castling.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect202 tok · 8831ms · claude-sonnet-4-6 · $0.0030

      Final pick: Nf3 — Knights before bishops principle: Nf3 directly contests e4 (Black's Nf6 eyes it), attacks d5, and prepares kingside castling. Per opening heuristic, tempo matters — passive play lets ...dxe4 equalize.. …

      • llm.reflect8831ms · $0.0030
      full reasoning
      Final pick: Nf3 — Knights before bishops principle: Nf3 directly contests e4 (Black's Nf6 eyes it), attacks d5, and prepares kingside castling. Per opening heuristic, tempo matters — passive play lets ...dxe4 equalize.. Rejected: b1c3, f1c4.
    • 9. Commit0 tok · 0ms

      Commit Nf3 (g1f3).

  6. 6...e5Haiku27.391 tok · $0.1368 · 235296ms
    • 1. Observe0 tok · 0ms

      Halbzug 6, Schwarz am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 30. Criticality: 0.30.

      • material-counter0ms
    • 2. Recall Position0 tok · 15ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search15ms
    • 3. Recall Opponent0 tok · 14ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search14ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan8629 tok · 73297ms · claude-haiku-4-5 · $0.0431

      Phase: opening. Develop pieces with tempo by attacking d4 via c5 or supporting d5 with c6. Maximize piece coordination to compensate for pawn deficit and prevent cramping. Complete development while sustaining central pr…

      • llm.plan73297ms · $0.0431
      full reasoning
      Phase: opening. Develop pieces with tempo by attacking d4 via c5 or supporting d5 with c6. Maximize piece coordination to compensate for pawn deficit and prevent cramping. Complete development while sustaining central presence. Transition to middlegame where Black's piece activity and c-file/e-file counterplay offset White's extra pawn. Critical: opponent threatens spatial squeeze via e4+d4 pawn duo and material advantage; own weakness: down one pawn, must develop fast and maintain forcing play; concrete tension: e4 attacked by d5 and Nf6; Black can generate tactics via piece coordination if move order favors attack.
    • 6. Candidates7176 tok · 60903ms · claude-haiku-4-5 · $0.0358

      Candidates: Nxe4 (Removes advanced e4 pawn, forces White's Queen centralization and disrupts pawn duo. Opens development tempo.) | dxe4 (Trades center pawns while maintaining d-file control. Opens lines for piece coordin…

      • chess.js.legal_moves0ms
      • llm.candidates60900ms · $0.0358
      full reasoning
      Candidates: Nxe4 (Removes advanced e4 pawn, forces White's Queen centralization and disrupts pawn duo. Opens development tempo.) | dxe4 (Trades center pawns while maintaining d-file control. Opens lines for piece coordination without losing tempo.) | e5 (Directly supports d5 and challenges d4, forces White's structural decision. Generates immediate tactical tension.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect11586 tok · 101044ms · claude-haiku-4-5 · $0.0579

      Final pick: e5 — Forces White's immediate decision on center structure. After Qxe5, Bg4 pins the Nf3 and generates forcing tactics. Opens d-file and maintains d5 pawn support. Creates tempo advantage.. Rejected: f6e4, d5…

      • llm.reflect101044ms · $0.0579
      full reasoning
      Final pick: e5 — Forces White's immediate decision on center structure. After Qxe5, Bg4 pins the Nf3 and generates forcing tactics. Opens d-file and maintains d5 pawn support. Creates tempo advantage.. Rejected: f6e4, d5e4.
    • 9. Commit0 tok · 0ms

      Commit e5 (e7e5).

  7. 7.Nc3Sonnet737 tok · $0.0109 · 30595ms
    • 1. Observe0 tok · 0ms

      Halbzug 7, Weiss am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 36. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan307 tok · 12585ms · claude-sonnet-4-6 · $0.0046

      Phase: opening. Complete minor piece development with Nc3 supporting the d4+e4 center, then develop bishop to c4 or e2, and castle kingside by move 6-7. Avoid pawn exchanges that release Black's central tension premature…

      • llm.plan12585ms · $0.0046
      full reasoning
      Phase: opening. Complete minor piece development with Nc3 supporting the d4+e4 center, then develop bishop to c4 or e2, and castle kingside by move 6-7. Avoid pawn exchanges that release Black's central tension prematurely. Maintain the classical pawn center (e4+d4) to cramp Black's pieces and transition into a space-dominant middlegame where White can attack on either wing after castling. Critical: Black's d5+e5 pawns create tension — do not release it carelessly with exd5 or dxe5; Per [OPENING knights before bishops]: Nc3 is the principled next move — develops with tempo, supports d4, avoids early queen exposure; Per [OPENING central control]: e4+d4 center must be maintained; Nc3 reinforces d4 against ...d5-d4 or ...exd4 pawn breaks; King safety: must castle within 2-3 moves — bishop on c4 or e2 clears the f1 square path.
    • 6. Candidates241 tok · 9045ms · claude-sonnet-4-6 · $0.0036

      Candidates: Nc3 (Knights before bishops principle: develops with tempo, reinforces d4 against Black's central breaks, clears path to castle.) | Bc4 (Classical development targeting f7, clears f1 for castling, maintains e…

      • chess.js.legal_moves0ms
      • llm.candidates9041ms · $0.0036
      full reasoning
      Candidates: Nc3 (Knights before bishops principle: develops with tempo, reinforces d4 against Black's central breaks, clears path to castle.) | Bc4 (Classical development targeting f7, clears f1 for castling, maintains e4+d4 central control without releasing tension.) | Be2 (Solid bishop development clears kingside for castling; king safety priority per plan — avoids overextension on c4.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect189 tok · 8942ms · claude-sonnet-4-6 · $0.0028

      Final pick: Nc3 — Knights before bishops: Nc3 reinforces d4 against ...exd4 or ...d4 pawn breaks, maintains classical e4+d4 center, and keeps bishop options open (c4 or e2) for the next move.. Rejected: f1c4, f1e2.

      • llm.reflect8942ms · $0.0028
    • 9. Commit0 tok · 0ms

      Commit Nc3 (b1c3).

  8. 8...Bg4Haiku9.784 tok · $0.0488 · 96969ms
    • 1. Observe0 tok · 0ms

      Halbzug 8, Schwarz am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 36. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan2044 tok · 22266ms · claude-haiku-4-5 · $0.0102

      Phase: opening. Develop pieces with tempo. Bg4 attacks f3 forcing a response, or c6 solidifies d5. Target: activate dark-squared bishop and queenside, challenge White's e4+d4 duo without trading into worse positions. Com…

      • llm.plan22266ms · $0.0102
      full reasoning
      Phase: opening. Develop pieces with tempo. Bg4 attacks f3 forcing a response, or c6 solidifies d5. Target: activate dark-squared bishop and queenside, challenge White's e4+d4 duo without trading into worse positions. Complete minor pieces by move 6-7 while maintaining central tension. Navigate into middlegame with fully coordinated pieces, counter White's space advantage via queenside/c-file activity and forcing tactics. Convert piece activity into compensation for any positional concession. Critical: White's e4+d4 pawn duo controls center; must exchange favourably or circumvent via flank play; Black's d5 pawn pinned by e4's control; development order critical to avoid cramping; Nf6 well-placed; f3 knight limits Black's dark-squared bishop—tempo moves (Bg4) exploit this.
    • 6. Candidates5558 tok · 49376ms · claude-haiku-4-5 · $0.0278

      Candidates: Bg4 (Pins knight to queen, forces immediate response. Activates bishop with tempo.) | Nxe4 (Captures e4 pawn, forces recapture. Tactical strike removes White's central anchor.) | c6 (Solidifies d5 pawn, preve…

      • chess.js.legal_moves0ms
      • llm.candidates49373ms · $0.0278
      full reasoning
      Candidates: Bg4 (Pins knight to queen, forces immediate response. Activates bishop with tempo.) | Nxe4 (Captures e4 pawn, forces recapture. Tactical strike removes White's central anchor.) | c6 (Solidifies d5 pawn, prevents Nd5, prepares queenside expansion with tempo.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect2182 tok · 25306ms · claude-haiku-4-5 · $0.0109

      Final pick: Bg4 — Pins Nf3 to queen with tempo. After h3 Ne4, Black's knight dominates center while defender pinned. Activates dark-squared bishop and launches forcing sequence.. Rejected: f6e4, c7c6.

      • llm.reflect25306ms · $0.0109
    • 9. Commit0 tok · 0ms

      Commit Bg4 (c8g4).

  9. 9.Be2Sonnet784 tok · $0.0117 · 29791ms
    • 1. Observe0 tok · 1ms

      Halbzug 9, Weiss am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 36. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 8ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search8ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan337 tok · 11977ms · claude-sonnet-4-6 · $0.0050

      Phase: opening. Complete development by moving the bishop off f1, then castle kingside. The Bg4 pin on Nf3 must be addressed — either Be2 to break the pin or h3 to chase the bishop. Maintain the e4+d4 center without rele…

      • llm.plan11977ms · $0.0050
      full reasoning
      Phase: opening. Complete development by moving the bishop off f1, then castle kingside. The Bg4 pin on Nf3 must be addressed — either Be2 to break the pin or h3 to chase the bishop. Maintain the e4+d4 center without releasing tension prematurely. Secure the kingside via castling, maintain the classical pawn center, and transition into a space-dominant middlegame where White's extra central control converts into a kingside attack. Critical: Black's Bg4 pins Nf3 against the queen — [OPENING knights before bishops] and [OPENING queen late] both flag this: releasing the pin is the immediate priority; Black's d5+e5 pawn duo contests the center — do not exchange with exd5 or dxe5 carelessly; King remains uncastled — [OPENING central control] is only useful if the king is safe; Be2 + 0-0 is the structural next step; h3 forcing Bh5 or Bxf3 is an option — Bxf3 gives Black the bishop pair but doubles White's pawns; Be2 is safer and directly enables castling.
    • 6. Candidates262 tok · 9415ms · claude-sonnet-4-6 · $0.0039

      Candidates: Be2 (Breaks Bg4 pin on Nf3, directly enables castling. King safety first — OPENING central control is useless with uncastled king.) | h3 (Chases Bg4 immediately. Forces Bh5 or Bxf3 — either resolves the pin a…

      • chess.js.legal_moves0ms
      • llm.candidates9412ms · $0.0039
      full reasoning
      Candidates: Be2 (Breaks Bg4 pin on Nf3, directly enables castling. King safety first — OPENING central control is useless with uncastled king.) | h3 (Chases Bg4 immediately. Forces Bh5 or Bxf3 — either resolves the pin and prepares g4. Addresses opponent threats before developing.) | Be3 (Develops bishop, supports d4 pawn, maintains central tension. OPENING knights before bishops already satisfied — bishop development now natural.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect185 tok · 8373ms · claude-sonnet-4-6 · $0.0027

      Final pick: Be2 — King safety first: Be2 breaks the Bg4 pin on Nf3 cleanly and enables immediate 0-0. No concessions — bishop stays active, center held, castling next move.. Rejected: h2h3, c1e3.

      • llm.reflect8373ms · $0.0027
    • 9. Commit0 tok · 0ms

      Commit Be2 (f1e2).

  10. 10...Nxe4Haiku4.901 tok · $0.0244 · 171790ms
    • 1. Observe0 tok · 1ms

      Halbzug 10, Schwarz am Zug. Phase: Eroeffnung. Material gleich. Legale Zuege: 38. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 4ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search4ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan2050 tok · 24274ms · claude-haiku-4-5 · $0.0102

      Phase: opening. Exploit Bg4 pin on f3 to disrupt White's development rhythm. Complete piece development (Nc6) while maintaining tactical compensation. Challenge d4+e4 via favorable central exchanges. Redirect White's spa…

      • llm.plan24274ms · $0.0102
      full reasoning
      Phase: opening. Exploit Bg4 pin on f3 to disrupt White's development rhythm. Complete piece development (Nc6) while maintaining tactical compensation. Challenge d4+e4 via favorable central exchanges. Redirect White's space advantage into active piece play on queenside. Enter middlegame with fully developed, coordinated minor pieces (Nc6, Nf6, Bg4, Bf5 or Bh5 variants) and queenside play (c6, potential b5/c5 thrusts) that compensates for White's initial space control. Critical: f3 knight pinned by Bg4 — White's options are restricted (move bishop, defend, block, or trade); d5 pawn under attack — Black must either support it (c6, Nbd7) or exchange favorably (exd4, dxe4); Black's piece development lag (2 vs 3 minors) must not persist past move 6 — Nc6 is almost forced; White's development acceleration (Nc3, Nf3, Be2 already out) means Black cannot afford slow moves; Tactical overextension trap — Bg4 is strong but moving it away from f3 loses the key forcing advantage.
    • 6. Candidates2851 tok · 27453ms · claude-haiku-4-5 · $0.0142

      Candidates: Nxe4 (Exploits Bg4 pin, centralizes knight with tempo. Forces White's center definition.) | exd4 (Challenges d4+e4 pawn duo via favorable exchange. Reduces White's space advantage.) | Nc6 (Completes piece dev…

      • chess.js.legal_moves0ms
      • llm.candidates27451ms · $0.0142
      full reasoning
      Candidates: Nxe4 (Exploits Bg4 pin, centralizes knight with tempo. Forces White's center definition.) | exd4 (Challenges d4+e4 pawn duo via favorable exchange. Reduces White's space advantage.) | Nc6 (Completes piece development. Coordinates with Bg4 for queenside pressure and c5/b5 ideas.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect0 tok · 120029ms · err:Claude CLI subprocess timed out after 120000ms

      Final pick: Nxe4 — Exploits Bg4 pin, centralizes knight with tempo. Forces White's center definition.. Rejected: e5d4, b8c6. [LLM note: Claude CLI subprocess timed out after 120000ms]

    • 9. Commit0 tok · 0ms

      Commit Nxe4 (f6e4).

  11. 11.O-OSonnet803 tok · $0.0119 · 35690ms
    • 1. Observe0 tok · 0ms

      Halbzug 11, Weiss am Zug. Phase: Eroeffnung. Schwarz +1 Punkte. Legale Zuege: 35. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan328 tok · 16286ms · claude-sonnet-4-6 · $0.0049

      Phase: opening. Break the Bg4 pin on Nf3 immediately via Be2, then castle kingside. After castling, maintain the d4+d5 central tension and develop the dark-squared bishop to a useful square. Avoid releasing central tensi…

      • llm.plan16286ms · $0.0049
      full reasoning
      Phase: opening. Break the Bg4 pin on Nf3 immediately via Be2, then castle kingside. After castling, maintain the d4+d5 central tension and develop the dark-squared bishop to a useful square. Avoid releasing central tension prematurely. Consolidate the classical pawn center, complete development, and transition into a space-dominant middlegame where White's extra central control converts into sustained pressure. Critical: Bg4 pins Nf3 against the queen — per [OPENING knights before bishops], this must be resolved before advancing any plan; Be2 breaks the pin cleanly while developing a piece; King is uncastled on e1 — [OPENING central control] heuristic flags that our center is strong but meaningless if the king is exposed; castling is the immediate priority after Be2; Black's Ne4 sits aggressively on e4 supported by the d5 pawn — Nxe4 or dxe5 must be evaluated to avoid letting the knight entrench further; Black is materially ahead (+1) suggesting we need active, not passive, play to justify the positional compensation.
    • 6. Candidates260 tok · 9502ms · claude-sonnet-4-6 · $0.0039

      Candidates: Bf1 (Breaks Bg4 pin on Nf3 by moving bishop away; king safety first — uncastled king on e1 is the priority per opening central control heuristic.) | O-O (King safety is paramount; castling immediately resolve…

      • chess.js.legal_moves0ms
      • llm.candidates9499ms · $0.0039
      full reasoning
      Candidates: Bf1 (Breaks Bg4 pin on Nf3 by moving bishop away; king safety first — uncastled king on e1 is the priority per opening central control heuristic.) | O-O (King safety is paramount; castling immediately resolves king exposure while preparing to contest the center from safety.) | Nxe4 (Eliminates Black's aggressively placed Ne4 before it entrenches; per opening knights before bishops heuristic, active piece removal improves our structure.)
    • 7. Verify0 tok · 2ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect215 tok · 9874ms · claude-sonnet-4-6 · $0.0032

      Final pick: O-O — King safety is the absolute priority per my structural backbone: uncastled king on e1 is a liability before any plan. O-O resolves king exposure immediately, connects rooks, and the Bg4 pin on Nf3 becom…

      • llm.reflect9874ms · $0.0032
      full reasoning
      Final pick: O-O — King safety is the absolute priority per my structural backbone: uncastled king on e1 is a liability before any plan. O-O resolves king exposure immediately, connects rooks, and the Bg4 pin on Nf3 becomes irrelevant once the king escapes the e-file.. Rejected: e2f1, c3e4.
    • 9. Commit0 tok · 0ms

      Commit O-O (e1g1).

  12. 12...Nc6Haiku10.538 tok · $0.0526 · 102027ms
    • 1. Observe0 tok · 0ms

      Halbzug 12, Schwarz am Zug. Phase: Eroeffnung. Schwarz +1 Punkte. Legale Zuege: 46. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 22ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search22ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan3275 tok · 30270ms · claude-haiku-4-5 · $0.0163

      Phase: opening. Develop Nc6 to attack d4 pawn with tempo. Maintain the active Ne4+Bg4 pin on f3. Create tactical compensation via piece coordination while completing development and pressure White's center. Enter middleg…

      • llm.plan30270ms · $0.0163
      full reasoning
      Phase: opening. Develop Nc6 to attack d4 pawn with tempo. Maintain the active Ne4+Bg4 pin on f3. Create tactical compensation via piece coordination while completing development and pressure White's center. Enter middlegame with fully coordinated pieces (Nc6, Nf6, active Bf5 or Bh5 variant) and queenside counterplay (c6, b5/c5 thrusts) that offsets White's space advantage via tactical activity. Critical: Nf3 pinned by Bg4 to d1 queen — exploit via Nc6 (attacking d4 with tempo) and keep Ne4 disrupting White's coordination; Black's d5 pawn under pressure from d4 — maintain control through Nc6 support and eventual Ne4-supported exchanges; Development lag (no Nc6, no Nf6, king not castled yet) — must accelerate without sacrificing the tactical pin advantage.
    • 6. Candidates3921 tok · 40927ms · claude-haiku-4-5 · $0.0196

      Candidates: Nc6 (Develops with tempo attacking d4, forcing White response while coordinating with Ne4) | Nxf2 (Tactical strike attacking queen, maintains compensation via active piece coordination) | exd4 (Simplifies cen…

      • chess.js.legal_moves0ms
      • llm.candidates40919ms · $0.0196
      full reasoning
      Candidates: Nc6 (Develops with tempo attacking d4, forcing White response while coordinating with Ne4) | Nxf2 (Tactical strike attacking queen, maintains compensation via active piece coordination) | exd4 (Simplifies center relieving d4 pressure while preserving Bg4 pin on f3)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect3342 tok · 30773ms · claude-haiku-4-5 · $0.0167

      Final pick: Nc6 — Develops with tempo, forces White's d4 defense, maintains Ne4+Bg4 pin. Coordinates pieces while keeping pressure and aligns with core middlegame plan.. Rejected: e4f2, e5d4.

      • llm.reflect30773ms · $0.0167
    • 9. Commit0 tok · 0ms

      Commit Nc6 (b8c6).

  13. 13.Nxe4Sonnet852 tok · $0.0127 · 38662ms
    • 1. Observe0 tok · 0ms

      Halbzug 13, Weiss am Zug. Phase: Eroeffnung. Schwarz +1 Punkte. Legale Zuege: 33. Criticality: 0.30.

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan375 tok · 12952ms · claude-sonnet-4-6 · $0.0056

      Phase: opening. Resolve the Bg4 pin on Nf3 via Be2, then castle kingside immediately. After castling, maintain d4/d5 central tension without releasing it prematurely. Use the Ne4 intrusion as a target to either exchange …

      • llm.plan12952ms · $0.0056
      full reasoning
      Phase: opening. Resolve the Bg4 pin on Nf3 via Be2, then castle kingside immediately. After castling, maintain d4/d5 central tension without releasing it prematurely. Use the Ne4 intrusion as a target to either exchange or expel with f3 after king safety is secured. Consolidate White's classical center (d4 supported, d5 contested), complete development, and convert spatial advantage into a dominant middlegame where Black's Ne4 becomes a liability rather than an asset. Critical: Bg4 pins Nf3 against Qd1 — per [OPENING knights before bishops], this pin must be broken before any plan proceeds; Be2 is the cleanest resolution; Ne4 sits aggressively on e4 but has no support — after castling, f3 can expel it at the right moment without weakening king structure; Per [OPENING central control], d4+d5 tension defines the position — do not trade d4 for e5 voluntarily; maintain the pawn mass; Black king is also uncastled (FEN shows kq rights) — White's priority is to castle first and deny Black easy kingside shelter; Nc6 is passive; no immediate threats beyond the Ne4 + Bg4 battery on the kingside.
    • 6. Candidates257 tok · 12624ms · claude-sonnet-4-6 · $0.0038

      Candidates: Nxe4 (Eliminates aggressive Ne4 outpost; per central control heuristic, removes Black's best piece while maintaining d4 pawn mass.) | Nxd5 (Strikes at d5 tension point; per opening knights before bishops, act…

      • chess.js.legal_moves0ms
      • llm.candidates12618ms · $0.0038
      full reasoning
      Candidates: Nxe4 (Eliminates aggressive Ne4 outpost; per central control heuristic, removes Black's best piece while maintaining d4 pawn mass.) | Nxd5 (Strikes at d5 tension point; per opening knights before bishops, active knight use before bishop development is principled here.) | h3 (Expels Bg4 pin on Nf3 immediately; per king safety first, breaking the pin restores full piece coordination before committing to a plan.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect220 tok · 13050ms · claude-sonnet-4-6 · $0.0033

      Final pick: Nxe4 — Per central control heuristic, Nxe4 removes Black's best-placed piece while keeping d4 intact. The Ne4 outpost was Black's only active piece; eliminating it leaves Black with a passive Nc6 and a now-us…

      • llm.reflect13050ms · $0.0033
      full reasoning
      Final pick: Nxe4 — Per central control heuristic, Nxe4 removes Black's best-placed piece while keeping d4 intact. The Ne4 outpost was Black's only active piece; eliminating it leaves Black with a passive Nc6 and a now-useless Bg4 with no pin target.. Rejected: c3d5, h2h3.
    • 9. Commit0 tok · 0ms

      Commit Nxe4 (c3e4).

  14. 14...exd4Haiku11.940 tok · $0.0596 · 111875ms
    • 1. Observe0 tok · 0ms

      Halbzug 14, Schwarz am Zug. Phase: Eroeffnung. Weiss +2 Punkte. Legale Zuege: 42. Criticality: 0.25.

      • material-counter0ms
    • 2. Recall Position0 tok · 11ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search11ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan2944 tok · 34264ms · claude-haiku-4-5 · $0.0147

      Phase: opening. Develop Nf6 with tempo against e4, maintain Bg4 pin on f3, complete piece development (dark bishop off f8), and sustain tactical counterplay to balance White's space advantage. Black transitions to middle…

      • llm.plan34264ms · $0.0147
      full reasoning
      Phase: opening. Develop Nf6 with tempo against e4, maintain Bg4 pin on f3, complete piece development (dark bishop off f8), and sustain tactical counterplay to balance White's space advantage. Black transitions to middlegame with full coordination (Nf6 + Be6/Bf5 + castling) while exploiting the pin on f3; dynamic compensation via piece activity rather than passive defense against White's d4/Ne4 dominance. Critical: White's Ne4 is centralized and active; d4 pawn anchors space advantage; Black underdeveloped: Nf6 missing, dark bishop stuck on f8; Bg4 pin is sole tactical asset; Nf6 gives tempo against e4; must follow through with Be6/Bf5 and completed development to avoid being slowly outmaneuvered.
    • 6. Candidates4536 tok · 38290ms · claude-haiku-4-5 · $0.0226

      Candidates: Nxd4 (Captures d4 with tempo, removes White's space anchor, forces recapture, maintains Bg4 pin) | dxe4 (Eliminates White's centralized Ne4 knight, reduces immediate tactical pressure, keeps piece coordinatio…

      • chess.js.legal_moves0ms
      • llm.candidates38287ms · $0.0226
      full reasoning
      Candidates: Nxd4 (Captures d4 with tempo, removes White's space anchor, forces recapture, maintains Bg4 pin) | dxe4 (Eliminates White's centralized Ne4 knight, reduces immediate tactical pressure, keeps piece coordination) | exd4 (Centralizes pawn, opens e-file for piece activity, sustains counterplay while maintaining pin pressure)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4460 tok · 39288ms · claude-haiku-4-5 · $0.0223

      Final pick: exd4 — Centralizes pawn on d4, opens e-file for piece activity, preserves Bg4 pin on f3. Sets up Nf6 next move to give tempo against e4. Maintains tactical counterplay while positioning for completed developm…

      • llm.reflect39288ms · $0.0223
      full reasoning
      Final pick: exd4 — Centralizes pawn on d4, opens e-file for piece activity, preserves Bg4 pin on f3. Sets up Nf6 next move to give tempo against e4. Maintains tactical counterplay while positioning for completed development.. Rejected: c6d4, d5e4.
    • 9. Commit0 tok · 0ms

      Commit exd4 (e5d4).

  15. 15.h3Sonnet809 tok · $0.0120 · 30966ms
    • 1. Observe0 tok · 1ms

      Halbzug 15, Weiss am Zug. Phase: Eroeffnung. Weiss +1 Punkte. Legale Zuege: 38. Criticality: 0.40.

      • material-counter0ms
    • 2. Recall Position0 tok · 15ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search15ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      research: opening_explorer + web_search both disabled — pure memory-only opening plan.

    • 5. Plan338 tok · 11921ms · claude-sonnet-4-6 · $0.0050

      Phase: opening. Break the Bg4 pin by playing Be2 (per [OPENING knights before bishops] — pin on Nf3 must be resolved), then castle kingside immediately to secure the king. After castling, maintain central tension d4/d5 a…

      • llm.plan11921ms · $0.0050
      full reasoning
      Phase: opening. Break the Bg4 pin by playing Be2 (per [OPENING knights before bishops] — pin on Nf3 must be resolved), then castle kingside immediately to secure the king. After castling, maintain central tension d4/d5 and assess whether Ne4 should retreat or hold its post. Convert White's classical center (d4 supported, e-file half-open) into a dominant middlegame by completing development, neutralizing Black's Bg4 pin, and then exploiting the advanced Ne4 as either a strong outpost or forcing Black to spend tempi addressing it. Critical: Bg4 pins Nf3 against Qd1 — per [OPENING knights before bishops] this is the #1 priority to resolve via Be2; King is uncastled on g1 — [OPENING central control] is useless if king safety is neglected; castling is mandatory next; Black's Nc6 and d5 contest the center — do not release d4/d5 tension prematurely, maintain space advantage; Ne4 is deeply placed but potentially unstable — after castling, f3 is an option to challenge it.
    • 6. Candidates251 tok · 9012ms · claude-sonnet-4-6 · $0.0037

      Candidates: h3 (Expels Bg4 pin on Nf3, restoring piece coordination. King safety via Be2+castle is top priority per opening principles.) | Bd3 (Breaks the pin indirectly by moving the bishop, activates it on strong diago…

      • chess.js.legal_moves0ms
      • llm.candidates9008ms · $0.0037
      full reasoning
      Candidates: h3 (Expels Bg4 pin on Nf3, restoring piece coordination. King safety via Be2+castle is top priority per opening principles.) | Bd3 (Breaks the pin indirectly by moving the bishop, activates it on strong diagonal, prepares kingside castling immediately.) | Nxd4 (Captures central pawn, eliminates pin target, simplifies while maintaining White's space advantage with Ne4 still active.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect220 tok · 9986ms · claude-sonnet-4-6 · $0.0033

      Final pick: h3 — Expels Bg4 directly, forcing the bishop to commit (h5 or e6/f5) before resolving the pin. Preserves Be2 for castling immediately next move. King safety is paramount — per opening principles, castle befor…

      • llm.reflect9986ms · $0.0033
      full reasoning
      Final pick: h3 — Expels Bg4 directly, forcing the bishop to commit (h5 or e6/f5) before resolving the pin. Preserves Be2 for castling immediately next move. King safety is paramount — per opening principles, castle before active piece play.. Rejected: e2d3, f3d4.
    • 9. Commit0 tok · 0ms

      Commit h3 (h2h3).

  16. 16...dxe4Haiku15.651 tok · $0.0781 · 143475ms
    • 1. Observe0 tok · 0ms

      Halbzug 16, Schwarz am Zug. Phase: Mittelspiel. Weiss +1 Punkte. Legale Zuege: 42. Criticality: 0.25.

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan5366 tok · 49892ms · claude-haiku-4-5 · $0.0268

      Phase: middlegame. Drive away White's strong Ne4 through tempo and development, secure the kingside via castling, and leverage the Bg4 pin to sustain tactical pressure and counterplay. Complete development while exploiti…

      • llm.plan49892ms · $0.0268
      full reasoning
      Phase: middlegame. Drive away White's strong Ne4 through tempo and development, secure the kingside via castling, and leverage the Bg4 pin to sustain tactical pressure and counterplay. Complete development while exploiting Bg4's pin and the advanced d4 pawn to neutralize White's space advantage. Target Ne4 for early trade or displacement to ease positional pressure. Critical: White's Ne4 anchors the entire advantage; must be displaced or traded early to relieve pressure; Black's kingside remains dangerously exposed (Bf8 undeveloped, king uncastled) until urgently secured; Bg4's pin on Nf3 is Black's sole tactical lever; maintaining or converting it into concessions is critical; White's h3 signals g4 expansion plans; Black must prepare resistance or accept further space loss.
    • 6. Candidates5783 tok · 51738ms · claude-haiku-4-5 · $0.0289

      Candidates: dxe4 (Removes White's strong Ne4 anchor, eases positional pressure. Advances central pawn with tactical tempo.) | Bxh3 (Removes h3, disrupts g4 expansion plans. Maintains Bg4 pin as sole tactical lever.) | Bx…

      • chess.js.legal_moves0ms
      • llm.candidates51734ms · $0.0289
      full reasoning
      Candidates: dxe4 (Removes White's strong Ne4 anchor, eases positional pressure. Advances central pawn with tactical tempo.) | Bxh3 (Removes h3, disrupts g4 expansion plans. Maintains Bg4 pin as sole tactical lever.) | Bxf3 (Exploits Nf3 pin directly, trades bishop for knight. Simplifies after White recaptures.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4502 tok · 41809ms · claude-haiku-4-5 · $0.0225

      Final pick: dxe4 — Strikes at White's Ne4 anchor directly, forces immediate recapture decision, eases positional pressure. Opens center for urgent kingside development and castling.. Rejected: g4h3, g4f3.

      • llm.reflect41809ms · $0.0225
    • 9. Commit0 tok · 0ms

      Commit dxe4 (d5e4).

  17. 17.Nxd4Sonnet765 tok · $0.0114 · 30188ms
    • 1. Observe0 tok · 0ms

      Halbzug 17, Weiss am Zug. Phase: Mittelspiel. Schwarz +2 Punkte. Legale Zuege: 33. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 11ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search11ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan327 tok · 12840ms · claude-sonnet-4-6 · $0.0049

      Phase: middlegame. Black has won material (+2) and threatens further pressure with Bg4 pinning and active pieces. White must consolidate king safety (already castled per previous plan), activate rooks on open/semi-open f…

      • llm.plan12840ms · $0.0049
      full reasoning
      Phase: middlegame. Black has won material (+2) and threatens further pressure with Bg4 pinning and active pieces. White must consolidate king safety (already castled per previous plan), activate rooks on open/semi-open files per [MIDDLE open file rooks], and target Black's d4/e4 pawn duo before they advance further. Undermine Black's advanced d4/e4 pawns using piece pressure and open file control, while neutralizing the Bg4 pin — the material deficit demands active counterplay rather than passive defense. Critical: Black's d4+e4 pawn duo cramps White severely — these must be attacked or blockaded immediately; Bg4 still pins or pressures the f3-knight; resolving this is priority one; Per [MIDDLE open file rooks]: e-file and d-file are semi-open for White — rooks need activation; King is castled (g1) — relatively safe but g2/h3 pawn structure needs monitoring given Black's bishop activity; Material deficit (-2) means White cannot trade down passively; must create imbalances.
    • 6. Candidates251 tok · 8894ms · claude-sonnet-4-6 · $0.0037

      Candidates: Nxd4 (Captures the advanced d4-pawn directly, eliminating the d4+e4 duo threat and activating the knight toward center.) | hxg4 (Eliminates the Bg4 pin immediately, resolving priority-one threat; opens h-file…

      • chess.js.legal_moves0ms
      • llm.candidates8889ms · $0.0037
      full reasoning
      Candidates: Nxd4 (Captures the advanced d4-pawn directly, eliminating the d4+e4 duo threat and activating the knight toward center.) | hxg4 (Eliminates the Bg4 pin immediately, resolving priority-one threat; opens h-file for rook activation per open-file principle.) | Bf4 (Develops bishop actively, targets e5 square, contests open files and creates counterplay without worsening king safety.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect187 tok · 8422ms · claude-sonnet-4-6 · $0.0028

      Final pick: Nxd4 — Eliminates the d4+e4 pawn duo immediately — per plan priority, these advanced pawns cramp White severely. Knight on d4 is centralized and active, recovering material while neutralizing Black's structur…

      • llm.reflect8422ms · $0.0028
      full reasoning
      Final pick: Nxd4 — Eliminates the d4+e4 pawn duo immediately — per plan priority, these advanced pawns cramp White severely. Knight on d4 is centralized and active, recovering material while neutralizing Black's structural advantage.. Rejected: h3g4, c1f4.
    • 9. Commit0 tok · 0ms

      Commit Nxd4 (f3d4).

  18. 18...Nxd4Haiku20.474 tok · $0.1023 · 229238ms
    • 1. Observe0 tok · 0ms

      Halbzug 18, Schwarz am Zug. Phase: Mittelspiel. Schwarz +1 Punkte. Legale Zuege: 45. Criticality: 0.25.

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2986 tok · 35272ms · claude-haiku-4-5 · $0.0149

      Phase: middlegame. Eliminate White's dominant Nd4 through direct capture, castle kingside to secure the king and complete piece development, then exploit the Bg4 pin to generate counterplay in a simplified position. Trad…

      • llm.plan35272ms · $0.0149
      full reasoning
      Phase: middlegame. Eliminate White's dominant Nd4 through direct capture, castle kingside to secure the king and complete piece development, then exploit the Bg4 pin to generate counterplay in a simplified position. Trade away White's space-anchoring knight, establish king safety via castling, and transition to a balanced middlegame where Black's Bg4 pin and developing pieces neutralize White's early advantage. Critical: White's Nd4 anchors the entire space advantage — must be removed in the next move or two to relieve pressure decisively; Black's uncastled king and undeveloped Bf8 remain dangerously exposed and invite tactics — castling is urgent after consolidating pieces; Black's Bg4 pin on Nf3 is the primary tactical leverage; must be exploited before White repositions — using it as a tempo tool to force exchanges favors Black's safety goals.
    • 6. Candidates13475 tok · 110905ms · claude-haiku-4-5 · $0.0673

      Candidates: Nxd4 (Removes White's dominant Nd4 via direct capture, balanced exchange (N for N), relieves Black's cramped position.) | Bc5 (Develops Bishop to aggressive square, attacks both Nd4 and f2 weakness, creates i…

      • chess.js.legal_moves0ms
      • llm.candidates110903ms · $0.0673
      full reasoning
      Candidates: Nxd4 (Removes White's dominant Nd4 via direct capture, balanced exchange (N for N), relieves Black's cramped position.) | Bc5 (Develops Bishop to aggressive square, attacks both Nd4 and f2 weakness, creates immediate dual threats.) | Bxh3 (Exploits h3 weakness, forces gxh3 opening g-file, weakens White's kingside, generates counter-play tempo.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4013 tok · 83016ms · claude-haiku-4-5 · $0.0200

      Final pick: Nxd4 — Direct removal of White's dominant anchor piece. Forces Qxd4, allowing Black to consolidate with immediate castling. Solves space disadvantage cleanly.. Rejected: f8c5, g4h3.

      • llm.reflect83016ms · $0.0200
    • 9. Commit0 tok · 0ms

      Commit Nxd4 (c6d4).

  19. 19.Qxd4Sonnet776 tok · $0.0115 · 31993ms
    • 1. Observe0 tok · 0ms

      Halbzug 19, Weiss am Zug. Phase: Mittelspiel. Schwarz +4 Punkte. Legale Zuege: 30. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 19ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search19ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan303 tok · 13547ms · claude-sonnet-4-6 · $0.0045

      Phase: middlegame. Activate the Bf1-e2 bishop and rooks to pressure Black's advanced d4/e4 pawns; neutralize the Bg4 pin; seek tactical counterplay against the overextended Ne4/d4 pawn duo before Black consolidates Conve…

      • llm.plan13547ms · $0.0045
      full reasoning
      Phase: middlegame. Activate the Bf1-e2 bishop and rooks to pressure Black's advanced d4/e4 pawns; neutralize the Bg4 pin; seek tactical counterplay against the overextended Ne4/d4 pawn duo before Black consolidates Convert activity and structural pressure on Black's isolated/advanced pawns into material recovery, accepting the deficit only if counterplay generates concrete threats Critical: Black Nd4 forks and e4 pawn advance threats are immediate; Bg4 pins White's f-pawn indirectly — bishop must be challenged or repositioned; Per [MIDDLE open file rooks]: rooks need activation on open/semi-open files (f-file most promising after f3 push); Per [MIDDLE isolated pawn IQP]: Black's d4 pawn has no c- or e-pawn neighbors — blockade square c3/e3 is a strategic target; White king on g1 is safe but pieces are passive — tempo is critical.
    • 6. Candidates255 tok · 8902ms · claude-sonnet-4-6 · $0.0038

      Candidates: Qxd4 (Wins back the d4 pawn immediately, eliminating Black's advanced IQP blockade threat and restoring material balance.) | hxg4 (Removes the Bg4 pin, opens h-file for rook activation per open-file rook heur…

      • chess.js.legal_moves0ms
      • llm.candidates8901ms · $0.0038
      full reasoning
      Candidates: Qxd4 (Wins back the d4 pawn immediately, eliminating Black's advanced IQP blockade threat and restoring material balance.) | hxg4 (Removes the Bg4 pin, opens h-file for rook activation per open-file rook heuristic, and challenges Black's bishop pair.) | Be3 (Develops the c1 bishop actively, targets d4 blockade square, and coordinates with queen — per IQP blockade principle.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect218 tok · 9495ms · claude-sonnet-4-6 · $0.0032

      Final pick: Qxd4 — Wins back the advanced d4 pawn immediately, restoring material balance and eliminating Black's IQP blockade threat. Per IQP principle, removing the d4 pawn before Black consolidates is highest priority…

      • llm.reflect9495ms · $0.0032
      full reasoning
      Final pick: Qxd4 — Wins back the advanced d4 pawn immediately, restoring material balance and eliminating Black's IQP blockade threat. Per IQP principle, removing the d4 pawn before Black consolidates is highest priority — structural clarity over speculative development.. Rejected: h3g4, c1e3.
    • 9. Commit0 tok · 0ms

      Commit Qxd4 (d1d4).

  20. 20...Bxe2Haiku14.791 tok · $0.0738 · 135357ms
    • 1. Observe0 tok · 0ms

      Halbzug 20, Schwarz am Zug. Phase: Mittelspiel. Schwarz +1 Punkte. Legale Zuege: 40. Criticality: 0.25.

      • material-counter0ms
    • 2. Recall Position0 tok · 18ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search18ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan5497 tok · 50775ms · claude-haiku-4-5 · $0.0274

      Phase: middlegame. Move Bg4 to safety (Bf5 or Bxe2), castle kingside immediately, and activate rooks on open files to equalize against White's space advantage. Secure king safety and complete development to transform Whi…

      • llm.plan50775ms · $0.0274
      full reasoning
      Phase: middlegame. Move Bg4 to safety (Bf5 or Bxe2), castle kingside immediately, and activate rooks on open files to equalize against White's space advantage. Secure king safety and complete development to transform White's space advantage into a balanced position with piece coordination and rook activity. Critical: Bg4 under attack from Ph3; move immediately to maintain activity or force White recapture; Black's uncastled king remains vulnerable to center and kingside attacks; O-O is urgent; White's Qd4 dominates the board; exchanging or displacing it reduces White's initiative and pressure; pe4 is advanced but weak; rook activation on the e-file could defend or exploit it; Both knights traded off; position relies on piece coordination over tactical maneuvers.
    • 6. Candidates5991 tok · 51777ms · claude-haiku-4-5 · $0.0299

      Candidates: Qxd4 (Exchange White's dominant centralized queen, reduce attacking potential, simplify position for consolidation) | Bxe2 (Capture bishop, maintain tactical pressure, force recapture to reposition White's qu…

      • chess.js.legal_moves0ms
      • llm.candidates51775ms · $0.0299
      full reasoning
      Candidates: Qxd4 (Exchange White's dominant centralized queen, reduce attacking potential, simplify position for consolidation) | Bxe2 (Capture bishop, maintain tactical pressure, force recapture to reposition White's queen from d4) | Bf5 (Move to active safe square away from h3 threat, maintain piece coordination, prepare development and castling)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect3303 tok · 32760ms · claude-haiku-4-5 · $0.0165

      Final pick: Bxe2 — Bxe2 forces White's recapture, displacing the dominant Qd4 and removing the hanging Bg4 while maintaining piece activity and disrupting White's initiative.. Rejected: d8d4, g4f5.

      • llm.reflect32760ms · $0.0165
    • 9. Commit0 tok · 0ms

      Commit Bxe2 (g4e2).

  21. 21.Qxd8+Sonnet1.674 tok · $0.0250 · 48613ms
    • 1. Observe0 tok · 0ms

      Halbzug 21, Weiss am Zug. Phase: Mittelspiel. Schwarz +4 Punkte. Legale Zuege: 40. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan1213 tok · 28754ms · claude-sonnet-4-6 · $0.0182

      Phase: middlegame. Capture the deeply infiltrated Be2 with Qxe2 to eliminate the immediate rook threat on f1, then manage the dangerous e4 pawn advance. Per [MIDDLE open file rooks]: activate Rf1 on the f-file after bish…

      • llm.plan28754ms · $0.0182
      full reasoning
      Phase: middlegame. Capture the deeply infiltrated Be2 with Qxe2 to eliminate the immediate rook threat on f1, then manage the dangerous e4 pawn advance. Per [MIDDLE open file rooks]: activate Rf1 on the f-file after bishop removal. Use the queen's centralization on e2/d3 to blockade the e-pawn. Trade the active Be2 to stabilize the position, accept the material deficit as a given, and use the queen plus rooks on semi-open files to create counterplay against Black's undeveloped queenside (Ra8, Qd8 still passive). Critical: Be2 attacks Rf1 — immediate removal or rook relocation required; e4 pawn will advance to e3 after Qxe2, forking f2/d2 — must be blockaded by queen; Per [MIDDLE isolated pawn IQP]: e4 pawn is advanced but isolated — blockade on e3 neutralizes long-term threat; Black Ra8/Qd8 are undeveloped — White can activate rooks on f- and e-files before Black consolidates; King safety: Kg1 is exposed after Be2 removal; f2 pawn is a weakness if e-pawn breaks through.
    • 6. Candidates247 tok · 8933ms · claude-sonnet-4-6 · $0.0037

      Candidates: Qxe4+ (Captures dangerous e4 pawn with check, removes immediate threat, centralizes queen per IQP blockade principle.) | Qxd8+ (Eliminates passive Qd8, forces king into open — exploits undeveloped queenside b…

      • chess.js.legal_moves0ms
      • llm.candidates8928ms · $0.0037
      full reasoning
      Candidates: Qxe4+ (Captures dangerous e4 pawn with check, removes immediate threat, centralizes queen per IQP blockade principle.) | Qxd8+ (Eliminates passive Qd8, forces king into open — exploits undeveloped queenside before Black consolidates.) | Re1 (Activates rook on e-file, attacks Be2 and supports e-file control per open file rooks heuristic.)
    • 7. Verify0 tok · 2ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect214 tok · 10875ms · claude-sonnet-4-6 · $0.0032

      Final pick: Qxd8+ — Eliminates Black's queen with check, forcing Kxd8 into the open — Black's undeveloped Ra8 can't defend. Per IQP blockade: removing Qd8 kills Black's coordination and leaves the e4 pawn orphaned withou…

      • llm.reflect10875ms · $0.0032
      full reasoning
      Final pick: Qxd8+ — Eliminates Black's queen with check, forcing Kxd8 into the open — Black's undeveloped Ra8 can't defend. Per IQP blockade: removing Qd8 kills Black's coordination and leaves the e4 pawn orphaned without queen support.. Rejected: d4e4, f1e1.
    • 9. Commit0 tok · 0ms

      Commit Qxd8+ (d4d8).

  22. 22...Rxd8Haiku12.066 tok · $0.0602 · 123781ms
    • 1. Observe0 tok · 0ms

      Halbzug 22, Schwarz am Zug. Phase: Mittelspiel. Weiss +5 Punkte. Legale Zuege: 2. Schach! Criticality: 0.45.

      • material-counter0ms
    • 2. Recall Position0 tok · 15ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search15ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan9359 tok · 88897ms · claude-haiku-4-5 · $0.0468

      Phase: middlegame. Resolve check by capturing White's dominant Queen on d8 (Raxd8 or Rhxd8), then consolidate King safety and activate Rooks on critical files for counterplay. After forced Queen capture, advance King to …

      • llm.plan88897ms · $0.0468
      full reasoning
      Phase: middlegame. Resolve check by capturing White's dominant Queen on d8 (Raxd8 or Rhxd8), then consolidate King safety and activate Rooks on critical files for counterplay. After forced Queen capture, advance King to safety (Kd7 or Ke7) and immediately activate Rooks on central and queenside files to neutralize White's space advantage. Critical: check forces immediate Queen capture with either Rook (Raxd8 or Rhxd8); King safety is critical after capture—must move away from center; Black's Be2 is extremely active and can pressure White's Bc1; White's remaining pieces (Bc1, Ra1, Rf1) are uncoordinated and passive; Black's e4 pawn controls central squares; exploit with Rook activity on open lines.
    • 6. Candidates966 tok · 14067ms · claude-haiku-4-5 · $0.0048

      Candidates: Rxd8 (Removes dominant Queen, activates Rook on d-file for central counterplay. Safer King position for consolidation.) | Kxd8 (Removes Queen, centralizes King but risks back-rank exposure. Less safe than Roo…

      • chess.js.legal_moves0ms
      • llm.candidates14066ms · $0.0048
      full reasoning
      Candidates: Rxd8 (Removes dominant Queen, activates Rook on d-file for central counterplay. Safer King position for consolidation.) | Kxd8 (Removes Queen, centralizes King but risks back-rank exposure. Less safe than Rook capture despite King activity.)
    • 7. Verify0 tok · 0ms

      Alle 2 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect1741 tok · 20781ms · claude-haiku-4-5 · $0.0087

      Final pick: Rxd8 — Activates Rook on d-file immediately, consolidates King safety (K remains e8), enables Be2+Rook coordination for central counterplay against White's passive pieces.. Rejected: e8d8.

      • llm.reflect20781ms · $0.0087
    • 9. Commit0 tok · 0ms

      Commit Rxd8 (a8d8).

  23. 23.Re1Sonnet676 tok · $0.0100 · 31346ms
    • 1. Observe0 tok · 0ms

      Halbzug 23, Weiss am Zug. Phase: Mittelspiel. Schwarz +4 Punkte. Legale Zuege: 21. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 6ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search6ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan247 tok · 12424ms · claude-sonnet-4-6 · $0.0037

      Phase: middlegame. Eliminate Be2 immediately to save Rf1, then blockade the e4 pawn with queen on e2/d3. Per [MIDDLE open file rooks], activate both rooks on f- and c-files to create counterplay against Black's passive q…

      • llm.plan12424ms · $0.0037
      full reasoning
      Phase: middlegame. Eliminate Be2 immediately to save Rf1, then blockade the e4 pawn with queen on e2/d3. Per [MIDDLE open file rooks], activate both rooks on f- and c-files to create counterplay against Black's passive queenside (Ra8, Qd8 undeveloped). Accept material deficit but neutralize Black's active pieces (Be2, e4 pawn) through queen centralization and rook activation on open files to exploit Black's undeveloped queenside. Critical: Be2 attacks Rf1 — must capture or lose exchange immediately; e4 pawn threatens to advance and queen on d8 can activate; own king on g1 exposed after h3 weakening — no immediate mating threats but watch Rd8-d2 infiltration.
    • 6. Candidates248 tok · 9398ms · claude-sonnet-4-6 · $0.0037

      Candidates: Re1 (Saves rook from Be2 attack, activates rook on open e-file to blockade e4 pawn and pressure Black's king.) | Bf4 (Develops bishop actively, attacks e5/d6 squares, indirectly pressures e4 pawn while openin…

      • chess.js.legal_moves0ms
      • llm.candidates9395ms · $0.0037
      full reasoning
      Candidates: Re1 (Saves rook from Be2 attack, activates rook on open e-file to blockade e4 pawn and pressure Black's king.) | Bf4 (Develops bishop actively, attacks e5/d6 squares, indirectly pressures e4 pawn while opening c1-rook.) | Be3 (Centralizes bishop, blocks e4 advance, supports rook activation on open files per middlegame plan.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect181 tok · 9500ms · claude-sonnet-4-6 · $0.0027

      Final pick: Re1 — Be2 attacks Rf1 — losing the exchange is immediate. Re1 saves the rook, lands on the open e-file blockading the e4 pawn, and activates the rook per the open-file principle.. Rejected: c1f4, c1e3.

      • llm.reflect9500ms · $0.0027
    • 9. Commit0 tok · 0ms

      Commit Re1 (f1e1).

  24. 24...Kd7Haiku12.906 tok · $0.0644 · 117221ms
    • 1. Observe0 tok · 0ms

      Halbzug 24, Schwarz am Zug. Phase: Mittelspiel. Schwarz +4 Punkte. Legale Zuege: 40. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 19ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search19ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan5460 tok · 44405ms · claude-haiku-4-5 · $0.0273

      Phase: middlegame. Move king to safety (Kd7/Ke7), activate both rooks on central/first-rank files to create threats, maintain Be2 pressure on Bc1, convert material advantage. Black consolidates +4 material advantage thro…

      • llm.plan44405ms · $0.0273
      full reasoning
      Phase: middlegame. Move king to safety (Kd7/Ke7), activate both rooks on central/first-rank files to create threats, maintain Be2 pressure on Bc1, convert material advantage. Black consolidates +4 material advantage through coordinated piece activation and creates multiple threats that force White into passive, losing defense. Critical: White's Bc1 under pressure from Black's Be2—forcing it to move gives Black tempo; Black's king on e8 is centralized and unsafe; must relocate (Kd7 or Ke7) immediately; Black's Rd8 controls d-file but must advance (Rd1/Rd2) to generate first-rank threats.
    • 6. Candidates2643 tok · 28980ms · claude-haiku-4-5 · $0.0132

      Candidates: Rd1 (First-rank domination forces White passive. Attacks Ra1, threatens back rank. Rook activation to first rank per plan.) | Rd2 (Second-rank pressure on a2/c2. Keeps rook active and coordinating with Be2. M…

      • chess.js.legal_moves0ms
      • llm.candidates28975ms · $0.0132
      full reasoning
      Candidates: Rd1 (First-rank domination forces White passive. Attacks Ra1, threatens back rank. Rook activation to first rank per plan.) | Rd2 (Second-rank pressure on a2/c2. Keeps rook active and coordinating with Be2. Maintains tempo in consolidation.) | Kd7 (King to safety, urgent per plan. Centralizes king, removes it from e8 weakness. Enables rook maneuvering next.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4803 tok · 43785ms · claude-haiku-4-5 · $0.0240

      Final pick: Kd7 — King safety urgent (plan-critical). d7 secures king from e8 vulnerability, enables Rd1 domination next move without back-rank worries. Consolidates material advantage safely.. Rejected: d8d1, d8d2.

      • llm.reflect43785ms · $0.0240
    • 9. Commit0 tok · 0ms

      Commit Kd7 (e8d7).

  25. 25.Rxe2Sonnet694 tok · $0.0103 · 27742ms
    • 1. Observe0 tok · 0ms

      Halbzug 25, Weiss am Zug. Phase: Mittelspiel. Schwarz +4 Punkte. Legale Zuege: 22. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 12ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search12ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan251 tok · 10382ms · claude-sonnet-4-6 · $0.0037

      Phase: middlegame. Capture Be2 with Re1xe2 to eliminate the active bishop and stop material loss, then blockade e4 with Re2-e3 or queen centralization. Per [MIDDLE open file rooks], activate rooks on open e- and c-files …

      • llm.plan10382ms · $0.0037
      full reasoning
      Phase: middlegame. Capture Be2 with Re1xe2 to eliminate the active bishop and stop material loss, then blockade e4 with Re2-e3 or queen centralization. Per [MIDDLE open file rooks], activate rooks on open e- and c-files to generate counterplay against Black's undeveloped queenside (Ra8, Rf8 passive). Trade the dangerous Be2 immediately, then use rook activity on open files to compensate for material deficit while Black's queenside remains dormant. Critical: Be2 attacks Re1 — immediate capture mandatory or lose exchange; e4 pawn chains with Be2 and threatens to advance to e3; own king on g1 exposed after h3 weakening; Black king on d7 is surprisingly exposed — open d-file and c-file counterplay possible.
    • 6. Candidates244 tok · 8408ms · claude-sonnet-4-6 · $0.0036

      Candidates: Rxe2 (Mandatory capture eliminates active Be2, stops material loss. Per open-file rooks heuristic, rook activates on e-file.) | Rd1+ (Checks exposed Black king on d7, opening d-file counterplay against undeve…

      • chess.js.legal_moves0ms
      • llm.candidates8407ms · $0.0036
      full reasoning
      Candidates: Rxe2 (Mandatory capture eliminates active Be2, stops material loss. Per open-file rooks heuristic, rook activates on e-file.) | Rd1+ (Checks exposed Black king on d7, opening d-file counterplay against undeveloped queenside per active rook heuristic.) | Be3 (Blockades dangerous e4 pawn, develops bishop to active central square while defending king safety.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect199 tok · 8917ms · claude-sonnet-4-6 · $0.0029

      Final pick: Rxe2 — Be2 attacks Re1 — capture is mandatory to avoid losing the exchange for nothing. Per open-file rooks heuristic, rook activates on e-file controlling e4 pawn and central counterplay.. Rejected: e1d1, c1…

      • llm.reflect8917ms · $0.0029
      full reasoning
      Final pick: Rxe2 — Be2 attacks Re1 — capture is mandatory to avoid losing the exchange for nothing. Per open-file rooks heuristic, rook activates on e-file controlling e4 pawn and central counterplay.. Rejected: e1d1, c1e3.
    • 9. Commit0 tok · 0ms

      Commit Rxe2 (e1e2).

  26. 26...e3Haiku12.859 tok · $0.0642 · 119939ms
    • 1. Observe0 tok · 0ms

      Halbzug 26, Schwarz am Zug. Phase: Mittelspiel. Schwarz +1 Punkte. Legale Zuege: 29. Criticality: 0.15.

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 10ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search10ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2987 tok · 30360ms · claude-haiku-4-5 · $0.0149

      Phase: middlegame. Leverage the +1 pawn material advantage by coordinating rooks on central and first-rank files. Deploy the e4 pawn as both a space-gaining weapon and a concrete threat that forces White's Re2 into react…

      • llm.plan30360ms · $0.0149
      full reasoning
      Phase: middlegame. Leverage the +1 pawn material advantage by coordinating rooks on central and first-rank files. Deploy the e4 pawn as both a space-gaining weapon and a concrete threat that forces White's Re2 into reactive defense. Activate the h8 rook from confinement and establish dual rook control of critical lines. Convert material advantage into a technically winning rook endgame by achieving rook penetration (d2, d1, or h-file activation), advancing e4 into a passed pawn candidate, and forcing White's pieces into defensive cramping until material loss or zugzwang becomes inevitable. Critical: e4 pawn is the concrete asset—currently locked by White's Re2. Displace Re2 or advance pawn (e3) to gain space and pass-pawn momentum.; Rook coordination: d8 rook must reach second/first rank (d2, d1) or support center. h8 rook must activate (h4 or via central file) instead of staying sidelined.; White's Bc1 and a1 rook are out of play. Black can force tempo and piece activity faster if rooks coordinate before White consolidates defenses..
    • 6. Candidates8143 tok · 69296ms · claude-haiku-4-5 · $0.0407

      Candidates: e3 (Advances e4 pawn per plan. Threatens e2 square, gains space and tempo.) | Kd6 (Centralizes king to support e4 pawn, frees d-file for rook penetration (Rd2/Rd1).) | Re8 (Controls e-file for rook coordinati…

      • chess.js.legal_moves0ms
      • llm.candidates69295ms · $0.0407
      full reasoning
      Candidates: e3 (Advances e4 pawn per plan. Threatens e2 square, gains space and tempo.) | Kd6 (Centralizes king to support e4 pawn, frees d-file for rook penetration (Rd2/Rd1).) | Re8 (Controls e-file for rook coordination. Prepares future penetration with d8-rook.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect1729 tok · 20250ms · claude-haiku-4-5 · $0.0086

      Final pick: e3 — Advances pawn to e3, forcing Re2 away immediately. Concrete threat, gains space, creates tempo. Displaces White's defender and unblocks the passed-pawn path.. Rejected: d7d6, d8e8.

      • llm.reflect20250ms · $0.0086
    • 9. Commit0 tok · 0ms

      Commit e3 (e4e3).

  27. 27.Rxe3Sonnet776 tok · $0.0115 · 31966ms
    • 1. Observe0 tok · 1ms

      Halbzug 27, Weiss am Zug. Phase: Mittelspiel. Schwarz +1 Punkte. Legale Zuege: 21. Criticality: 0.15.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan302 tok · 12880ms · claude-sonnet-4-6 · $0.0045

      Phase: middlegame. Neutralize the e3 pawn threat immediately — it promotes or wins material. Activate rooks on the open e-file per [MIDDLE open file rooks] to generate counterplay. Coordinate Rc1 and Re2 to create mating…

      • llm.plan12880ms · $0.0045
      full reasoning
      Phase: middlegame. Neutralize the e3 pawn threat immediately — it promotes or wins material. Activate rooks on the open e-file per [MIDDLE open file rooks] to generate counterplay. Coordinate Rc1 and Re2 to create mating threats or win back material while Black's queenside (Ra8, Rf8) remains dormant. Use rook dominance on the e-file and open lines to compensate for material deficit, targeting Black's exposed king on d7 while stopping the e3 passer from promoting. Critical: e3 pawn is one step from promotion — must be captured or blockaded immediately; Black king on d7 is exposed — e-file rook pressure could generate serious threats; Own king on g1 is relatively safe but Ra1 is passive — [MIDDLE open file rooks] demands both rooks on e-file or active files; Black's Ra8 and Rf8 are undeveloped — time is on White's side if material can be stabilized.
    • 6. Candidates245 tok · 9610ms · claude-sonnet-4-6 · $0.0036

      Candidates: Bxe3 (Bishop captures the dangerous e3 passer immediately, keeping king safe and opening diagonal for counterplay.) | Rxe3 (Rook captures e3 pawn, activating the e-file per open-file rook principle and pressu…

      • chess.js.legal_moves0ms
      • llm.candidates9609ms · $0.0036
      full reasoning
      Candidates: Bxe3 (Bishop captures the dangerous e3 passer immediately, keeping king safe and opening diagonal for counterplay.) | Rxe3 (Rook captures e3 pawn, activating the e-file per open-file rook principle and pressuring exposed Black king on d7.) | fxe3 (Pawn recapture eliminates e3 threat, opens f-file for rook activation without conceding material.)
    • 7. Verify0 tok · 3ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect229 tok · 9429ms · claude-sonnet-4-6 · $0.0034

      Final pick: Rxe3 — Rook captures e3 eliminating the passer while landing on the open e-file, directly pressuring the exposed Black king on d7. Per [MIDDLE open file rooks], the rook belongs on e3/e-file generating immedi…

      • llm.reflect9429ms · $0.0034
      full reasoning
      Final pick: Rxe3 — Rook captures e3 eliminating the passer while landing on the open e-file, directly pressuring the exposed Black king on d7. Per [MIDDLE open file rooks], the rook belongs on e3/e-file generating immediate threats, not passively recapturing with pawns or bishop.. Rejected: c1e3, f2e3.
    • 9. Commit0 tok · 0ms

      Commit Rxe3 (e2e3).

  28. 28...Re8Haiku15.244 tok · $0.0761 · 133809ms
    • 1. Observe0 tok · 1ms

      Halbzug 28, Schwarz am Zug. Phase: Mittelspiel. Material gleich. Legale Zuege: 25. Criticality: 0.15.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 10ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search10ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2674 tok · 23346ms · claude-haiku-4-5 · $0.0133

      Phase: middlegame. Activate d8 rook on semi-open d-file. Threaten d2 or d1 infiltration. Coordinate both rooks for dual control on central lines within 3-5 moves. Convert pawn advantage into technical win by achieving ro…

      • llm.plan23346ms · $0.0133
      full reasoning
      Phase: middlegame. Activate d8 rook on semi-open d-file. Threaten d2 or d1 infiltration. Coordinate both rooks for dual control on central lines within 3-5 moves. Convert pawn advantage into technical win by achieving rook penetration (d2/d1), cramping White's pieces, and transitioning to a won rook endgame. Critical: h8 rook passive—activate on h-file or d-file immediately for pressure; white re3 active on rank 3—vulnerable to rook penetration from below; d-file semi-open—primary breakthrough route; d2 is weak square; back-rank tactics: black king d7 central but undefended second rank needs care.
    • 6. Candidates3303 tok · 29310ms · claude-haiku-4-5 · $0.0165

      Candidates: Kd6 (Clears d-file immediately. King centralizes. Threatens Rd1/Rd2 infiltration next move, forcing White's hand.) | Re8 (Activates d8 rook on e-file. Threatens e2/e1 infiltration. Prepares dual rook control …

      • chess.js.legal_moves0ms
      • llm.candidates29309ms · $0.0165
      full reasoning
      Candidates: Kd6 (Clears d-file immediately. King centralizes. Threatens Rd1/Rd2 infiltration next move, forcing White's hand.) | Re8 (Activates d8 rook on e-file. Threatens e2/e1 infiltration. Prepares dual rook control on central lines.) | Bd6 (Activates f8 bishop. Improves piece coordination. Supports d2 infiltration and central control.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect9267 tok · 81107ms · claude-haiku-4-5 · $0.0463

      Final pick: Re8 — Re8 creates immediate forcing threats (Re1+ is check on the e-file, forcing White's king to move). More direct than Kd6's slow positional buildup. Rook active with concrete tactical leverage.. Rejected:…

      • llm.reflect81107ms · $0.0463
      full reasoning
      Final pick: Re8 — Re8 creates immediate forcing threats (Re1+ is check on the e-file, forcing White's king to move). More direct than Kd6's slow positional buildup. Rook active with concrete tactical leverage.. Rejected: d7d6, f8d6.
    • 9. Commit0 tok · 0ms

      Commit Re8 (d8e8).

  29. 29.Re7+Sonnet709 tok · $0.0105 · 30898ms
    • 1. Observe0 tok · 0ms

      Halbzug 29, Weiss am Zug. Phase: Mittelspiel. Material gleich. Legale Zuege: 29. Criticality: 0.15.

      • material-counter0ms
    • 2. Recall Position0 tok · 16ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search16ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan303 tok · 12376ms · claude-sonnet-4-6 · $0.0045

      Phase: middlegame. Activate rooks on the open e-file per [MIDDLE open file rooks] — doubled rooks on the e-file pressure Black's exposed king on d7. Coordinate Re3 and Ra1 to target e7/e8 and restrict Black's rooks from …

      • llm.plan12376ms · $0.0045
      full reasoning
      Phase: middlegame. Activate rooks on the open e-file per [MIDDLE open file rooks] — doubled rooks on the e-file pressure Black's exposed king on d7. Coordinate Re3 and Ra1 to target e7/e8 and restrict Black's rooks from becoming active. Force Black to defend passively while creating mating threats along the e-file. Dominate the e-file with doubled rooks to generate decisive threats against Black's exposed king on d7, converting rook activity into a decisive advantage before Black's queenside rooks can coordinate. Critical: Black king on d7 is exposed — e-file pressure directly threatens Re7+ or Re8+ mating patterns; Per [MIDDLE open file rooks]: Re3 already controls e-file; doubling with Ra1-e1 creates maximum pressure; Black's Re8 and Rf8 are passive — must act before they activate and neutralize our initiative; No immediate Black threats — we have tempo to improve rook coordination without defensive urgency.
    • 6. Candidates253 tok · 9053ms · claude-sonnet-4-6 · $0.0038

      Candidates: Re7+ (Checks exposed king on d7 directly; per open-file rooks heuristic, rook on 7th rank creates maximum pressure and restricts king.) | Rxe8 (Captures passive Black rook on e8, eliminating defender while do…

      • chess.js.legal_moves0ms
      • llm.candidates9051ms · $0.0038
      full reasoning
      Candidates: Re7+ (Checks exposed king on d7 directly; per open-file rooks heuristic, rook on 7th rank creates maximum pressure and restricts king.) | Rxe8 (Captures passive Black rook on e8, eliminating defender while dominating open e-file per doubled-rook plan.)
    • 7. Verify0 tok · 1ms

      Alle 2 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect153 tok · 9430ms · claude-sonnet-4-6 · $0.0023

      Final pick: Re7+ — Check forces Black king to move, surrendering e8 rook next move. Per open-file rooks heuristic, rook on 7th rank simultaneously checks king and attacks e8 rook — double threat wins material immediately…

      • llm.reflect9430ms · $0.0023
      full reasoning
      Final pick: Re7+ — Check forces Black king to move, surrendering e8 rook next move. Per open-file rooks heuristic, rook on 7th rank simultaneously checks king and attacks e8 rook — double threat wins material immediately.. Rejected: e3e8.
    • 9. Commit0 tok · 0ms

      Commit Re7+ (e3e7).

  30. 30...Kxe7Haiku25.423 tok · $0.1270 · 211162ms
    • 1. Observe0 tok · 1ms

      Halbzug 30, Schwarz am Zug. Phase: Mittelspiel. Material gleich. Legale Zuege: 7. Schach! Criticality: 0.50.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan6726 tok · 59260ms · claude-haiku-4-5 · $0.0336

      Phase: middlegame. Escape check with a move that improves piece centralization. Activate both rooks on semi-open d-file and central files within 3-5 moves. Neutralize White's initiative and position for rook penetration …

      • llm.plan59260ms · $0.0336
      full reasoning
      Phase: middlegame. Escape check with a move that improves piece centralization. Activate both rooks on semi-open d-file and central files within 3-5 moves. Neutralize White's initiative and position for rook penetration into White's position. Consolidate piece coordination on open lines, achieve dual-rook pressure on central files, and convert material advantage (extra pawn) into a technically winning rook + pawn endgame. Critical: Immediate threat: White Re7 gives check and dominates the board—must be eliminated or deflected while improving Black's piece placement; Black's h8 rook is completely passive and uninvolved—reactivate it on d-file or e-file to create dual rook pressure and central control; Extra pawn is a long-term asset but requires coordinated, active pieces to convert into endgame advantage; structure toward rook penetration and pawn promotion.
    • 6. Candidates12276 tok · 95445ms · claude-haiku-4-5 · $0.0613

      Candidates: Rxe7 (Activates e8 rook to strong 7th rank, removes checking piece, centralizes piece on key file.) | Kxe7 (Centralizes king on e7 while removing check, positions king to support rook infiltration.) | Bxe7 (R…

      • chess.js.legal_moves0ms
      • llm.candidates95444ms · $0.0613
      full reasoning
      Candidates: Rxe7 (Activates e8 rook to strong 7th rank, removes checking piece, centralizes piece on key file.) | Kxe7 (Centralizes king on e7 while removing check, positions king to support rook infiltration.) | Bxe7 (Removes checking piece, consolidates centralization. Less direct rook activation but maintains tactical flexibility.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6421 tok · 56423ms · claude-haiku-4-5 · $0.0321

      Final pick: Kxe7 — Centralizes king on e7 for endgame, immediately opens d-file for h8 rook jump to d8, enables rapid dual-rook coordination on central files.. Rejected: e8e7, f8e7.

      • llm.reflect56423ms · $0.0321
    • 9. Commit0 tok · 0ms

      Commit Kxe7 (d7e7).

  31. 31.Bg5+Sonnet1.031 tok · $0.0154 · 36186ms
    • 1. Observe0 tok · 0ms

      Halbzug 31, Weiss am Zug. Phase: Mittelspiel. Schwarz +5 Punkte. Legale Zuege: 20. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 20ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search20ms
    • 3. Recall Opponent0 tok · 13ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search13ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan579 tok · 17275ms · claude-sonnet-4-6 · $0.0086

      Phase: middlegame. Activate Ra1 to e1, deliver check on e-file to force Black king to a worse square, then coordinate Bc1 to threaten discovered or mating ideas. Per [MIDDLE open file rooks]: the e-file is open and Black…

      • llm.plan17275ms · $0.0086
      full reasoning
      Phase: middlegame. Activate Ra1 to e1, deliver check on e-file to force Black king to a worse square, then coordinate Bc1 to threaten discovered or mating ideas. Per [MIDDLE open file rooks]: the e-file is open and Black's king sits on e7 — Re1+ is the immediate lever. Force king displacement before Black consolidates with Re8 defense. Exploit the exposed Black king on e7 via e-file pressure with Re1+ and bishop coordination to generate enough tactical compensation to offset the material deficit before Black's queenside pawns advance. Critical: Black king on e7 is directly on the open e-file — Re1+ wins tempo; Black Re8 blocks own king's retreat to f8/d8 after check; White is down ~5 material points so speed is essential — no slow plans; Per [MIDDLE open file rooks]: doubled rooks on e-file is the standard winning template here — Ra1 must reach e1 this move.
    • 6. Candidates260 tok · 9916ms · claude-sonnet-4-6 · $0.0039

      Candidates: Bg5+ (Delivers check forcing king displacement; per open e-file rook principle, gains tempo to activate Ra1-e1 next move.) | Be3 (Develops bishop toward e-file coordination; prepares Re1+ plan while improving…

      • chess.js.legal_moves0ms
      • llm.candidates9915ms · $0.0039
      full reasoning
      Candidates: Bg5+ (Delivers check forcing king displacement; per open e-file rook principle, gains tempo to activate Ra1-e1 next move.) | Be3 (Develops bishop toward e-file coordination; prepares Re1+ plan while improving worst piece per positional improvement heuristic.) | Rb1 (Rook activation step; per open-file rooks heuristic, rook must reach e1 — Rb1 is a stepping stone though Be3/Bg5+ are faster.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect192 tok · 8948ms · claude-sonnet-4-6 · $0.0028

      Final pick: Bg5+ — Delivers check immediately, forcing king displacement from e7 — per open e-file rooks heuristic, this gains a free tempo to play Ra1-e1 next, activating the rook with check threats before Black consoli…

      • llm.reflect8948ms · $0.0028
      full reasoning
      Final pick: Bg5+ — Delivers check immediately, forcing king displacement from e7 — per open e-file rooks heuristic, this gains a free tempo to play Ra1-e1 next, activating the rook with check threats before Black consolidates Re8.. Rejected: c1e3, a1b1.
    • 9. Commit0 tok · 0ms

      Commit Bg5+ (c1g5).

  32. 32...Ke6Haiku12.534 tok · $0.0626 · 126130ms
    • 1. Observe0 tok · 0ms

      Halbzug 32, Schwarz am Zug. Phase: Mittelspiel. Schwarz +5 Punkte. Legale Zuege: 4. Schach! Criticality: 0.55.

      • material-counter0ms
    • 2. Recall Position0 tok · 12ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search12ms
    • 3. Recall Opponent0 tok · 4ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search4ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan5046 tok · 46420ms · claude-haiku-4-5 · $0.0252

      Phase: middlegame. Escape Bg5 check while preserving rook placement. Activate e8 and h8 rooks on central or d-file within 3-4 moves. Convert +1 pawn advantage into coordinated rook pressure and winning endgame. Trade pie…

      • llm.plan46420ms · $0.0252
      full reasoning
      Phase: middlegame. Escape Bg5 check while preserving rook placement. Activate e8 and h8 rooks on central or d-file within 3-4 moves. Convert +1 pawn advantage into coordinated rook pressure and winning endgame. Trade pieces toward rook + pawn endgame where Black's extra pawn and superior structure guarantee victory. Critical: Opponent threat: Bg5 gives check on f6-e7-d8 diagonal; careless king moves allow repeated checks; Own weakness: e8 rook blocked by king on e7; h8 rook underdeveloped; both must activate soon; Concrete tactic: White Ra1 is passive but could threaten back rank (Ra7+) or invade d-file if Black's pieces stay uncoordinated.
    • 6. Candidates2498 tok · 30300ms · claude-haiku-4-5 · $0.0125

      Candidates: Kd6 (Optimal king centralization for rook endgame, opens e-file for Re8 activation, supports queenside pawn thrust.) | Ke6 (Centralizes king toward center, immediately unblocks e8 rook for d-file action, incr…

      • chess.js.legal_moves0ms
      • llm.candidates30299ms · $0.0125
      full reasoning
      Candidates: Kd6 (Optimal king centralization for rook endgame, opens e-file for Re8 activation, supports queenside pawn thrust.) | Ke6 (Centralizes king toward center, immediately unblocks e8 rook for d-file action, increases pressure on White's back rank.) | Kd7 (Unblocks e8 rook, maintains king safety while preparing d-file dominance via Re8-d8, flexible positioning.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4990 tok · 49380ms · claude-haiku-4-5 · $0.0249

      Final pick: Ke6 — Maximum centralization: e6 is the board's most active king square here, unblocks e8 rook for immediate d-file seizing (Re8-d8 next), supports queenside pawns from center, controls d5/f5/e5. Flexibility …

      • llm.reflect49380ms · $0.0249
      full reasoning
      Final pick: Ke6 — Maximum centralization: e6 is the board's most active king square here, unblocks e8 rook for immediate d-file seizing (Re8-d8 next), supports queenside pawns from center, controls d5/f5/e5. Flexibility to play both e-file and d-file rook strategies.. Rejected: e7d6, e7d7.
    • 9. Commit0 tok · 0ms

      Commit Ke6 (e7e6).

  33. 33.Re1+Sonnet704 tok · $0.0105 · 31262ms
    • 1. Observe0 tok · 0ms

      Halbzug 33, Weiss am Zug. Phase: Mittelspiel. Schwarz +5 Punkte. Legale Zuege: 28. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 4ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search4ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan267 tok · 12877ms · claude-sonnet-4-6 · $0.0040

      Phase: middlegame. Maintain e-file pressure via Re1+ to keep Black king displaced, coordinate bishop on g5 to threaten mating or winning material, force Black into passive defense before queenside pawns become decisive. …

      • llm.plan12877ms · $0.0040
      full reasoning
      Phase: middlegame. Maintain e-file pressure via Re1+ to keep Black king displaced, coordinate bishop on g5 to threaten mating or winning material, force Black into passive defense before queenside pawns become decisive. Exploit the exposed Black king on e6 with rook-bishop battery threats to generate tactical compensation offsetting the material deficit, aiming for perpetual check or material recovery. Critical: Black king on e6 remains exposed — [MIDDLE open file rooks] confirms Re1+ as primary lever to deny king shelter; Bg5 is actively placed; bishop coordination with rook on e-file creates mating threats that Black must address; Black's material advantage (+5) means simplification favors Black — White must keep the position complex and king in danger; Black Re8 would close the e-file and stabilize; Re1+ must precede that consolidation move.
    • 6. Candidates248 tok · 9397ms · claude-sonnet-4-6 · $0.0037

      Candidates: Re1+ (MIDDLE open file rooks: Re1+ displaces Black king on e6, denying consolidation via Re8 and keeping position complex.) | Bf6 (Trade only when you gain: Bf6 attacks h8-rook, forces material concession and…

      • chess.js.legal_moves0ms
      • llm.candidates9396ms · $0.0037
      full reasoning
      Candidates: Re1+ (MIDDLE open file rooks: Re1+ displaces Black king on e6, denying consolidation via Re8 and keeping position complex.) | Bf6 (Trade only when you gain: Bf6 attacks h8-rook, forces material concession and disrupts Black's coordination.) | Be7 (King safety first: Be7 traps Black bishop on f8, restricts king flight squares, maintaining mating pressure on exposed king.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect189 tok · 8955ms · claude-sonnet-4-6 · $0.0028

      Final pick: Re1+ — Re1+ exploits the open e-file immediately, forcing the Black king to move before Re8 consolidates. MIDDLE open file rooks confirms this is the primary lever — king on e6 stays displaced, position remai…

      • llm.reflect8954ms · $0.0028
      full reasoning
      Final pick: Re1+ — Re1+ exploits the open e-file immediately, forcing the Black king to move before Re8 consolidates. MIDDLE open file rooks confirms this is the primary lever — king on e6 stays displaced, position remains complex, offsetting Black's material edge.. Rejected: g5f6, g5e7.
    • 9. Commit0 tok · 0ms

      Commit Re1+ (a1e1).

  34. 34...Kd5Haiku13.983 tok · $0.0698 · 131716ms
    • 1. Observe0 tok · 1ms

      Halbzug 34, Schwarz am Zug. Phase: Mittelspiel. Schwarz +5 Punkte. Legale Zuege: 4. Schach! Criticality: 0.55.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan8937 tok · 81109ms · claude-haiku-4-5 · $0.0446

      Phase: middlegame. Black can force a decisive material advantage through check sequences. Execute the most forcing move available, then consolidate rook domination to drive toward endgame victory where Black's material i…

      • llm.plan81109ms · $0.0446
      full reasoning
      Phase: middlegame. Black can force a decisive material advantage through check sequences. Execute the most forcing move available, then consolidate rook domination to drive toward endgame victory where Black's material is overwhelming. Convert forcing tactics into material advantage (win White's rook), then coordinate both rooks for board domination and technical endgame conversion. Critical: Immediate tactic: Multiple checks available. Prioritize moves that win material and maintain initiative simultaneously.; After forcing sequence: Black will have overwhelming material (2R+B vs B+P). Shift focus to technical conversion—activate both rooks, create mating nets, drive to resignable position.; White is in crisis. Bg5 and h3 are non-factors after material swing. Press relentlessly without allowing counterplay..
    • 6. Candidates2654 tok · 25248ms · claude-haiku-4-5 · $0.0132

      Candidates: Kd5 (Centralizes king toward White king, dominates with rooks for decisive mating attack.) | Kf5 (Aggressive kingside activation, attacks h3, coordinates with rooks for forcing mating net.) | Kd7 (Maintains c…

      • chess.js.legal_moves0ms
      • llm.candidates25248ms · $0.0132
      full reasoning
      Candidates: Kd5 (Centralizes king toward White king, dominates with rooks for decisive mating attack.) | Kf5 (Aggressive kingside activation, attacks h3, coordinates with rooks for forcing mating net.) | Kd7 (Maintains central control, improves positioning for coordinated two-rook attack consolidation.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect2392 tok · 25319ms · claude-haiku-4-5 · $0.0119

      Final pick: Kd5 — Centralizes king aggressively toward White king. Supports coordinated rook attack, pressures loose Re1, and maintains forcing initiative for two-rook endgame conversion.. Rejected: e6f5, e6d7.

      • llm.reflect25319ms · $0.0119
    • 9. Commit0 tok · 0ms

      Commit Kd5 (e6d5).

  35. 35.Re5+Sonnet696 tok · $0.0103 · 27932ms
    • 1. Observe0 tok · 0ms

      Halbzug 35, Weiss am Zug. Phase: Mittelspiel. Schwarz +5 Punkte. Legale Zuege: 35. Criticality: 0.20.

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 14ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search14ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan267 tok · 10876ms · claude-sonnet-4-6 · $0.0040

      Phase: middlegame. Exploit Black king on d5 with Re1+ or Re5+ to drive it further into the open, coordinate Bg5 to create mating threats or win material, deny king shelter on queenside before Black consolidates Use rook-…

      • llm.plan10876ms · $0.0040
      full reasoning
      Phase: middlegame. Exploit Black king on d5 with Re1+ or Re5+ to drive it further into the open, coordinate Bg5 to create mating threats or win material, deny king shelter on queenside before Black consolidates Use rook-bishop battery on the open e-file to generate perpetual check or material recovery sufficient to offset the -5 material deficit, keeping Black king permanently displaced Critical: Black king exposed on d5 — primary target, no shelter; Re1 sits on open e-file per [MIDDLE open file rooks] — must activate it with check immediately; Bg5 well-placed but needs rook coordination to create real threats; Black Re8 and Rh8 are passive but can activate if White loses initiative; Material deficit (-5) means White cannot trade off into a quiet endgame — must press now.
    • 6. Candidates245 tok · 8516ms · claude-sonnet-4-6 · $0.0036

      Candidates: Re5+ (Checks Black king on open e-file per [open file rooks], driving it further into open where Bg5 coordinates threats.) | c4+ (Pawn check displaces Black king, gains tempo, opens diagonal — forces king int…

      • chess.js.legal_moves0ms
      • llm.candidates8513ms · $0.0036
      full reasoning
      Candidates: Re5+ (Checks Black king on open e-file per [open file rooks], driving it further into open where Bg5 coordinates threats.) | c4+ (Pawn check displaces Black king, gains tempo, opens diagonal — forces king into worse square before consolidation.) | Rxe8 (Trades passive rook for Black's Re8, reducing material deficit; per [trade only when you gain] this simplifies advantageously.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect184 tok · 8500ms · claude-sonnet-4-6 · $0.0027

      Final pick: Re5+ — Re5+ checks the exposed king on d5, per [open file rooks] heuristic — forces king further into open where Bg5 coordinates. Maintains initiative critical given -5 material deficit.. Rejected: c2c4, e1e8…

      • llm.reflect8500ms · $0.0027
      full reasoning
      Final pick: Re5+ — Re5+ checks the exposed king on d5, per [open file rooks] heuristic — forces king further into open where Bg5 coordinates. Maintains initiative critical given -5 material deficit.. Rejected: c2c4, e1e8.
    • 9. Commit0 tok · 0ms

      Commit Re5+ (e1e5).

  36. 36...Kxe5Haiku13.103 tok · $0.0654 · 123958ms
    • 1. Observe0 tok · 0ms

      Halbzug 36, Schwarz am Zug. Phase: Mittelspiel. Schwarz +5 Punkte. Legale Zuege: 6. Schach! Criticality: 0.35.

      • material-counter0ms
    • 2. Recall Position0 tok · 12ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search12ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3185 tok · 33297ms · claude-haiku-4-5 · $0.0159

      Phase: middlegame. Execute forcing check sequence (Re1+) to maintain tempo and improve rook coordination. Within 3–5 moves, aim to win material, dominate the e-file, or secure overwhelming endgame advantage. Convert Blac…

      • llm.plan33297ms · $0.0159
      full reasoning
      Phase: middlegame. Execute forcing check sequence (Re1+) to maintain tempo and improve rook coordination. Within 3–5 moves, aim to win material, dominate the e-file, or secure overwhelming endgame advantage. Convert Black's material superiority and active pieces into a technically dominant endgame by forcing White's King into a mating net through coordinated rook control. Critical: White Rook on e5 is exposed and blocks Black's Re8 from e-file domination; Black's h-rook must be activated into the attack for full board control; Multiple forcing checks available (Re1+); maintain tempo and initiative to prevent White consolidation; White King g1 is vulnerable; restrict mobility through checks to force tactical advantage.
    • 6. Candidates3162 tok · 31333ms · claude-haiku-4-5 · $0.0158

      Candidates: Rxe5 (Captures exposed White Rook. Rook dominates e-file, frees e-file for h-rook activation, wins decisive material advantage.) | Kxe5 (King captures rook, aggressive centralization on e5. Maintains tempo, t…

      • chess.js.legal_moves0ms
      • llm.candidates31332ms · $0.0158
      full reasoning
      Candidates: Rxe5 (Captures exposed White Rook. Rook dominates e-file, frees e-file for h-rook activation, wins decisive material advantage.) | Kxe5 (King captures rook, aggressive centralization on e5. Maintains tempo, threatens White King g1, converts material into mating attack.) | Kd4 (Centralizes king, threatens Kxe5 next move. Forces White reaction, maintains flexibility, controls key central squares.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6756 tok · 59295ms · claude-haiku-4-5 · $0.0337

      Final pick: Kxe5 — Centralizes king aggressively on e5. Re1+ forcing check follows next move. King dominates board, threatens White King escape, maximizes attacking potential.. Rejected: e8e5, d5d4.

      • llm.reflect59295ms · $0.0337
    • 9. Commit0 tok · 0ms

      Commit Kxe5 (d5e5).

  37. 37.Bf4+Sonnet737 tok · $0.0109 · 32503ms
    • 1. Observe0 tok · 0ms

      Halbzug 37, Weiss am Zug. Phase: Mittelspiel. Schwarz +10 Punkte. Legale Zuege: 23. Criticality: 0.10. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 12ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search12ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan270 tok · 11908ms · claude-sonnet-4-6 · $0.0040

      Phase: middlegame. Drive Black king further into the open with checks, coordinate Bg5 and rook on open e-file per [MIDDLE open file rooks] heuristic to generate perpetual check or mating threats that offset the material …

      • llm.plan11908ms · $0.0040
      full reasoning
      Phase: middlegame. Drive Black king further into the open with checks, coordinate Bg5 and rook on open e-file per [MIDDLE open file rooks] heuristic to generate perpetual check or mating threats that offset the material deficit Use rook-bishop battery on open e-file to keep Black king permanently displaced and extract maximum counterplay before material deficit becomes decisive in an endgame. Critical: Black king exposed on e5 — primary target, no pawn shelter; Material deficit -10 points means quiet play loses; only active checking saves; Bg5 on strong diagonal, rook on e-file per [MIDDLE open file rooks] must coordinate immediately; Black rooks on e8 and h8 — Re8 can interpose checks, reducing perpetual options; No own weaknesses relevant — king safe on g1, pawns passive but not targeted.
    • 6. Candidates238 tok · 10093ms · claude-sonnet-4-6 · $0.0035

      Candidates: Bf6+ (Direct check forces king to move, keeps bishop active on open diagonal per open-file coordination heuristic.) | Bf4+ (Check displaces exposed king further, bishop stays on strong diagonal; exploits king…

      • chess.js.legal_moves0ms
      • llm.candidates10092ms · $0.0035
      full reasoning
      Candidates: Bf6+ (Direct check forces king to move, keeps bishop active on open diagonal per open-file coordination heuristic.) | Bf4+ (Check displaces exposed king further, bishop stays on strong diagonal; exploits king shelter weakness per middlegame heuristic.) | f4+ (Pawn check drives king off e5, opens f-file, coordinates with rook battery on open files to maximize pressure.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect229 tok · 10471ms · claude-sonnet-4-6 · $0.0034

      Final pick: Bf4+ — Bf4+ checks king on e5 and repositions bishop to f4 controlling d2-h6 diagonal — king cannot go to d4 (Bf4 covers) or f6 (Bf6 next), forcing king further from safety. Bishop stays maximally active per …

      • llm.reflect10471ms · $0.0034
      full reasoning
      Final pick: Bf4+ — Bf4+ checks king on e5 and repositions bishop to f4 controlling d2-h6 diagonal — king cannot go to d4 (Bf4 covers) or f6 (Bf6 next), forcing king further from safety. Bishop stays maximally active per open-file coordination heuristic.. Rejected: g5f6, f2f4.
    • 9. Commit0 tok · 0ms

      Commit Bf4+ (g5f4).

  38. 38...Kxf4Haiku7.522 tok · $0.0375 · 78998ms
    • 1. Observe0 tok · 0ms

      Halbzug 38, Schwarz am Zug. Phase: Mittelspiel. Schwarz +10 Punkte. Legale Zuege: 7. Schach! Criticality: 0.35.

      • material-counter0ms
    • 2. Recall Position0 tok · 22ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search22ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2039 tok · 22747ms · claude-haiku-4-5 · $0.0102

      Phase: middlegame. Execute Re1+ forcing sequence to maintain tempo, dominate e-file with coordinated rooks, confine White's king, and activate h-rook for overwhelming pressure within 3–5 moves. Convert Black's overwhelmi…

      • llm.plan22747ms · $0.0102
      full reasoning
      Phase: middlegame. Execute Re1+ forcing sequence to maintain tempo, dominate e-file with coordinated rooks, confine White's king, and activate h-rook for overwhelming pressure within 3–5 moves. Convert Black's overwhelming material advantage (two rooks + bishop vs single bishop) into rapid technical victory via forced king confinement and coordinated piece pressure. Critical: White king g1 critically exposed with limited escape squares; Re1+ initiates forcing check sequence improving rook coordination; h-rook activation essential for board saturation and tempo maintenance; Prevent White's bishop from generating perpetual checks; push toward technically won endgame.
    • 6. Candidates3051 tok · 30249ms · claude-haiku-4-5 · $0.0152

      Candidates: Kxf4 (Captures bishop, eliminates checking threats, centralizes Black king for dominant endgame and tempo control) | Ke4 (Centralizes king on e-file supporting rook coordination, advances toward White king, m…

      • chess.js.legal_moves0ms
      • llm.candidates30249ms · $0.0152
      full reasoning
      Candidates: Kxf4 (Captures bishop, eliminates checking threats, centralizes Black king for dominant endgame and tempo control) | Ke4 (Centralizes king on e-file supporting rook coordination, advances toward White king, maintains overwhelming pressure) | Kd4 (Aggressively centralizes king, restricts White king escape squares, supports coordinated rook dominance)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect2432 tok · 25955ms · claude-haiku-4-5 · $0.0121

      Final pick: Kxf4 — Captures bishop, eliminates checking threats, centralizes king, forces technically won endgame with 2 rooks vs pawns. Rejected: e5e4, e5d4.

      • llm.reflect25955ms · $0.0121
    • 9. Commit0 tok · 0ms

      Commit Kxf4 (e5f4).

  39. 39.g3+Sonnet659 tok · $0.0098 · 32857ms
    • 1. Observe0 tok · 0ms

      Halbzug 39, Weiss am Zug. Phase: Mittelspiel. Schwarz +13 Punkte. Legale Zuege: 13. Criticality: 0.10. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan240 tok · 10414ms · claude-sonnet-4-6 · $0.0036

      Phase: middlegame. Force perpetual check or mating net around Black king on f4 using rook activity and king coordination — the only path given -13 material deficit Exploit Black king's total exposure on f4 (no pawn shelt…

      • llm.plan10414ms · $0.0036
      full reasoning
      Phase: middlegame. Force perpetual check or mating net around Black king on f4 using rook activity and king coordination — the only path given -13 material deficit Exploit Black king's total exposure on f4 (no pawn shelter, open files) via [MIDDLE open file rooks] heuristic — place rook on e-file or f-file to deliver checks and prevent Black king from finding shelter, turning material deficit irrelevant through perpetual or mating attack. Critical: Black king on f4 is exposed but moving toward safety — every tempo counts; No pieces remain except rook vs rook+bishop — perpetual check is primary survival mechanism; Per [MIDDLE open file rooks]: rook must reach f- or e-file immediately to generate checks before Black king escapes to queenside safety.
    • 6. Candidates252 tok · 9375ms · claude-sonnet-4-6 · $0.0037

      Candidates: g3+ (Delivers check immediately, forcing Black king to move; per open file/check pressure heuristic, every tempo matters with king on f4.) | f3 (Cuts off king retreat to f3/e3, tightening mating net; king saf…

      • chess.js.legal_moves0ms
      • llm.candidates9375ms · $0.0037
      full reasoning
      Candidates: g3+ (Delivers check immediately, forcing Black king to move; per open file/check pressure heuristic, every tempo matters with king on f4.) | f3 (Cuts off king retreat to f3/e3, tightening mating net; king safety principle — restrict opponent king before pursuing perpetual.) | Kf1 (Activates king toward center coordination; per king safety first heuristic, improving worst piece (passive king) to support perpetual check sequence.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect167 tok · 13037ms · claude-sonnet-4-6 · $0.0025

      Final pick: g3+ — Delivers immediate check forcing Black king off f4. Per [MIDDLE open file rooks] heuristic, every tempo matters — g3+ gains a move while the king on f4 has zero shelter, keeping perpetual check alive.. …

      • llm.reflect13037ms · $0.0025
      full reasoning
      Final pick: g3+ — Delivers immediate check forcing Black king off f4. Per [MIDDLE open file rooks] heuristic, every tempo matters — g3+ gains a move while the king on f4 has zero shelter, keeping perpetual check alive.. Rejected: f2f3, g1f1.
    • 9. Commit0 tok · 0ms

      Commit g3+ (g2g3).

  40. 40...Ke4Haiku6.164 tok · $0.0307 · 67779ms
    • 1. Observe0 tok · 0ms

      Halbzug 40, Schwarz am Zug. Phase: Mittelspiel. Schwarz +13 Punkte. Legale Zuege: 5. Schach! Criticality: 0.55.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 14ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search14ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2431 tok · 26914ms · claude-haiku-4-5 · $0.0121

      Phase: middlegame. Force White king into h-file corner via Re1+ and coordinated rook invasion. Saturate back rank and e-file with both rooks, activate h-rook for mating attack. Deliver forced mate or convert to resignati…

      • llm.plan26914ms · $0.0121
      full reasoning
      Phase: middlegame. Force White king into h-file corner via Re1+ and coordinated rook invasion. Saturate back rank and e-file with both rooks, activate h-rook for mating attack. Deliver forced mate or convert to resignation within 3–5 moves. Exploit White's catastrophic king exposure by confining it to h1/h2 corner, coordinate rooks for dual-file control, use bishop support for final mating blow. Rapid technical victory from overwhelming material advantage. Critical: White king g1 critically exposed (h1/h2/f1 only escapes); Re1+ forces king move while improving rook coordination and e-file dominance; h-rook activation mandatory after king displacement via h1+ check or back-rank invasion; No White counterplay available; execution is purely technical.
    • 6. Candidates1434 tok · 16401ms · claude-haiku-4-5 · $0.0071

      Candidates: Ke5 (Centralizes king, supports e-file for Re1+ tactical blow, coordinates rooks for mating attack.) | Ke4 (Most aggressive centralization, controls critical squares, tightens mating net with rook coordinatio…

      • chess.js.legal_moves0ms
      • llm.candidates16400ms · $0.0071
      full reasoning
      Candidates: Ke5 (Centralizes king, supports e-file for Re1+ tactical blow, coordinates rooks for mating attack.) | Ke4 (Most aggressive centralization, controls critical squares, tightens mating net with rook coordination.) | Kf5 (Advances kingside, supports bishop and h-rook for final mating assault on cornered White king.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect2299 tok · 24420ms · claude-haiku-4-5 · $0.0115

      Final pick: Ke4 — Most aggressive centralization. Controls e3, d3, d4, d5, e5, f3, f5. Supports Re1+ forcing sequence and backs mating attack after king displacement.. Rejected: f4e5, f4f5.

      • llm.reflect24420ms · $0.0115
    • 9. Commit0 tok · 0ms

      Commit Ke4 (f4e4).

  41. 41.f3+Sonnet728 tok · $0.0108 · 36448ms
    • 1. Observe0 tok · 0ms

      Halbzug 41, Weiss am Zug. Phase: Endspiel. Schwarz +13 Punkte. Legale Zuege: 14. Criticality: 0.10. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 12ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search12ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan300 tok · 18557ms · claude-sonnet-4-6 · $0.0045

      Phase: endgame. Survive and seek perpetual check or stalemate trick — Black is +13 material with rook+bishop vs our lone rook; no realistic winning path exists for White, only drawing resources through rook activity and …

      • llm.plan18557ms · $0.0045
      full reasoning
      Phase: endgame. Survive and seek perpetual check or stalemate trick — Black is +13 material with rook+bishop vs our lone rook; no realistic winning path exists for White, only drawing resources through rook activity and king shelter Use rook to harass Black king and create perpetual check threats, exploiting the [ENDGAME philidor rook] principle to keep rook active behind or beside enemy pawns rather than passively defending — the only drawing resource at -13 material Critical: Black king on e4 is centralized and dangerous — our king must not be mated; Black has rook+bishop vs our lone rook — material is overwhelming, draw is the ceiling; Philidor/Lucena heuristics from memory are secondary here — perpetual check via rook checks on open ranks/files is primary drawing resource; White king on g1 is safe for now but must stay coordinated with rook to avoid back-rank mate; 14 legal moves suggest reasonable mobility — rook should seek active checking squares, not passive defense.
    • 6. Candidates244 tok · 9443ms · claude-sonnet-4-6 · $0.0036

      Candidates: f3+ (Immediate check on Black king at e4 forces king movement, gaining tempo and activating drawing resource via king harassment.) | Kh2 (King safety first principle: stepping off back rank to h2 avoids poten…

      • chess.js.legal_moves0ms
      • llm.candidates9443ms · $0.0036
      full reasoning
      Candidates: f3+ (Immediate check on Black king at e4 forces king movement, gaining tempo and activating drawing resource via king harassment.) | Kh2 (King safety first principle: stepping off back rank to h2 avoids potential back-rank mate threats while keeping drawing options open.) | g4 (Pawn advance restricts Black king's shelter approach and creates space; pawn structure tension per endgame heuristics to complicate position.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect184 tok · 8414ms · claude-sonnet-4-6 · $0.0027

      Final pick: f3+ — Immediate check forces Black king to move, disrupting coordination between Black's rook+bishop. Active rook harassment via f3+ is the only drawing resource at -13 material — Philidor principle demands r…

      • llm.reflect8414ms · $0.0027
      full reasoning
      Final pick: f3+ — Immediate check forces Black king to move, disrupting coordination between Black's rook+bishop. Active rook harassment via f3+ is the only drawing resource at -13 material — Philidor principle demands rook activity, not passive king moves.. Rejected: g1h2, g3g4.
    • 9. Commit0 tok · 0ms

      Commit f3+ (f2f3).

  42. 42...Kxf3Haiku15.819 tok · $0.0790 · 141934ms
    • 1. Observe0 tok · 0ms

      Halbzug 42, Schwarz am Zug. Phase: Endspiel. Schwarz +13 Punkte. Legale Zuege: 6. Schach! Criticality: 0.35.

      • material-counter0ms
    • 2. Recall Position0 tok · 15ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search15ms
    • 3. Recall Opponent0 tok · 10ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search10ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3716 tok · 35306ms · claude-haiku-4-5 · $0.0185

      Phase: endgame. Re1+ forces White king toward h-file corner. Follow with Rh1/Rh2 coordinating both rooks for mating attack within 3–5 moves. Exploit overwhelming material (R+B+pawns vs pawns alone) and trapped king to de…

      • llm.plan35306ms · $0.0185
      full reasoning
      Phase: endgame. Re1+ forces White king toward h-file corner. Follow with Rh1/Rh2 coordinating both rooks for mating attack within 3–5 moves. Exploit overwhelming material (R+B+pawns vs pawns alone) and trapped king to deliver forced checkmate. Critical: White king on g1 has no safe escape: Re1+ forces Kh2, Kf1, or Kh1, all leading to mating nets; Black rooks must saturate back rank and h-file simultaneously to prevent king flight; Bishop on f8 controls dark squares, blocks escape routes, supports mating blow; White has zero counterplay: pawns alone cannot defend, cannot give checks, cannot create threats; Execution critical: each move must give check or threaten mate to maintain forcing tempo.
    • 6. Candidates5676 tok · 49784ms · claude-haiku-4-5 · $0.0283

      Candidates: Kxf3 (Captures defender, advances king into attack, forces Kh2 then Rh1# or Kf2 with unstoppable mate.) | Kd5 (Centralizes king safely, clears e-file for rook maneuvers, maintains pressure in mating sequence.…

      • chess.js.legal_moves0ms
      • llm.candidates49783ms · $0.0283
      full reasoning
      Candidates: Kxf3 (Captures defender, advances king into attack, forces Kh2 then Rh1# or Kf2 with unstoppable mate.) | Kd5 (Centralizes king safely, clears e-file for rook maneuvers, maintains pressure in mating sequence.) | Ke5 (Centralizes king toward attack, supports rook coordination, prepares forcing continuation with Re1+ tactics.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6427 tok · 56808ms · claude-haiku-4-5 · $0.0321

      Final pick: Kxf3 — Captures defender, advances King into attack. Enables Re1+ with King actively supporting mating net on h-file. Most forcing.. Rejected: e4d5, e4e5.

      • llm.reflect56808ms · $0.0321
    • 9. Commit0 tok · 0ms

      Commit Kxf3 (e4f3).

  43. 43.Kh1Sonnet677 tok · $0.0100 · 30357ms
    • 1. Observe0 tok · 0ms

      Halbzug 43, Weiss am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 11. Criticality: 0.10. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 19ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search19ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan251 tok · 12896ms · claude-sonnet-4-6 · $0.0037

      Phase: endgame. Activate rook aggressively to create perpetual check threats or force stalemate — avoid passive play. King must escape to a safe square while rook harasses Black king or attacks pawns to create counter-th…

      • llm.plan12896ms · $0.0037
      full reasoning
      Phase: endgame. Activate rook aggressively to create perpetual check threats or force stalemate — avoid passive play. King must escape to a safe square while rook harasses Black king or attacks pawns to create counter-threats. Hold the draw through rook activity based on Philidor principles — keep rook on active files, give checks to disrupt Black coordination, and seek stalemate traps if material falls further. Critical: Black king on f3 is dangerously close — our king on g1 is nearly mated, must assess mating threats immediately; Philidor rook heuristic: rook must stay active, not passive — checks and pawn harassment are the only drawing resources; Black has rook+bishop superiority; any rook trade would likely be lost — avoid simplification, keep rook alive and mobile.
    • 6. Candidates229 tok · 8932ms · claude-sonnet-4-6 · $0.0034

      Candidates: Kf1 (Philidor principle: king escapes mating net, moves away from Black king on f3 to safer square.) | Kh1 (King safety first: retreat to corner avoids immediate mate threats from Black king on f3.) | g4 (Heu…

      • chess.js.legal_moves0ms
      • llm.candidates8932ms · $0.0034
      full reasoning
      Candidates: Kf1 (Philidor principle: king escapes mating net, moves away from Black king on f3 to safer square.) | Kh1 (King safety first: retreat to corner avoids immediate mate threats from Black king on f3.) | g4 (Heuristic-aligned pawn advance creates space and stalemate trap potential, disrupting Black coordination.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect197 tok · 8490ms · claude-sonnet-4-6 · $0.0029

      Final pick: Kh1 — King safety first: Kh1 retreats to corner, maximizing distance from Black king on f3. Philidor principle — keep king safe before seeking active counterplay. h1 avoids Ke2/Kf2 mating nets and preserves s…

      • llm.reflect8490ms · $0.0029
      full reasoning
      Final pick: Kh1 — King safety first: Kh1 retreats to corner, maximizing distance from Black king on f3. Philidor principle — keep king safe before seeking active counterplay. h1 avoids Ke2/Kf2 mating nets and preserves stalemate trap potential in the corner.. Rejected: g1f1, g3g4.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (g1h1).

  44. 44...Re1+Haiku20.523 tok · $0.1025 · 184544ms
    • 1. Observe0 tok · 0ms

      Halbzug 44, Schwarz am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 34. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan6576 tok · 55814ms · claude-haiku-4-5 · $0.0328

      Phase: endgame. Execute forced checkmate within 3-5 moves. Play Re1+ forcing king to h2 or g2, then coordinate both rooks (Rh1, Rh2) to seal escape routes. White's pawns cannot defend; only resistance is king mobility. F…

      • llm.plan55814ms · $0.0328
      full reasoning
      Phase: endgame. Execute forced checkmate within 3-5 moves. Play Re1+ forcing king to h2 or g2, then coordinate both rooks (Rh1, Rh2) to seal escape routes. White's pawns cannot defend; only resistance is king mobility. Force checkmate by saturating rank 1 and h-file with coordinated rooks, trapping White's king while the bishop controls dark-square escape routes. Critical: White king on h1 has only h2 and g2 as escape squares after Re1+; Black rooks must synchronize rank 1 and h-file to lock down all exits; White pawns provide zero defense—king escape is the only hope for White; Bishop on f8 supports by controlling long diagonal and denying counterplay.
    • 6. Candidates4627 tok · 45269ms · claude-haiku-4-5 · $0.0231

      Candidates: Re1+ (Forcing check drives White king to h2/g2, initiates mating attack with coordinated rooks) | Kxg3 (Activates king, eliminates h3 pawn defender, strengthens kingside attack for checkmate net) | Rg8 (Prepa…

      • chess.js.legal_moves0ms
      • llm.candidates45267ms · $0.0231
      full reasoning
      Candidates: Re1+ (Forcing check drives White king to h2/g2, initiates mating attack with coordinated rooks) | Kxg3 (Activates king, eliminates h3 pawn defender, strengthens kingside attack for checkmate net) | Rg8 (Prepares second rook to join h-file or 1st rank for coordinated mating squeeze of White king)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect9320 tok · 83425ms · claude-haiku-4-5 · $0.0466

      Final pick: Re1+ — Re1+ forces the king to h2 or g2, then synchronize rooks on h-file and first rank to deliver checkmate. Coordinates both rooks for mate within 3-5 moves.. Rejected: f3g3, h8g8.

      • llm.reflect83425ms · $0.0466
    • 9. Commit0 tok · 0ms

      Commit Re1+ (e8e1).

  45. 45.Kh2Sonnet359 tok · $0.0053 · 17867ms
    • 1. Observe0 tok · 0ms

      Halbzug 45, Weiss am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 1. Schach! Criticality: 0.55. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 19ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search19ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan255 tok · 10946ms · claude-sonnet-4-6 · $0.0038

      Phase: endgame. With only 1 legal move available, execute it. Black is +14 material and our king is nearly mated on h1 — the position is lost. Seek any perpetual check or stalemate trap through rook activity; if none exi…

      • llm.plan10946ms · $0.0038
      full reasoning
      Phase: endgame. With only 1 legal move available, execute it. Black is +14 material and our king is nearly mated on h1 — the position is lost. Seek any perpetual check or stalemate trap through rook activity; if none exist, resign is warranted per system recommendation. Survive through rook harassment using the Philidor active-rook principle — keep the rook giving checks rather than passive defense, force Black into stalemate if king gets cornered, accept the draw if found. Critical: Only 1 legal move — no choice in execution; Black rook on e1 delivers mate threats; our king on h1 is in a mating net; Philidor heuristic: rook must stay active not passive — checks are the only drawing weapon; AUFGABE (resignation) recommended by engine — material floor at -14 makes survival extremely unlikely.
    • 6. Candidates104 tok · 6885ms · claude-sonnet-4-6 · $0.0015

      Candidates: Kh2 (Only legal move. King safety first — escaping h1 mating net. Philidor active-rook heuristic irrelevant with zero alternatives.)

      • chess.js.legal_moves0ms
      • llm.candidates6884ms · $0.0015
    • 7. Verify0 tok · 0ms

      Alle 1 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect0 tok · 0ms

      Final pick: Kh2 — Only legal move. King safety first — escaping h1 mating net. Philidor active-rook heuristic irrelevant with zero alternatives.. Rejected: —.

    • 9. Commit0 tok · 0ms

      Commit Kh2 (h1h2).

  46. 46...Re2+Haiku19.742 tok · $0.0986 · 179020ms
    • 1. Observe0 tok · 0ms

      Halbzug 46, Schwarz am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 36. Criticality: 0.20.

      • material-counter0ms
    • 2. Recall Position0 tok · 9ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search9ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan5713 tok · 56285ms · claude-haiku-4-5 · $0.0285

      Phase: endgame. Restrict White king to back-rank corner using coordinated rook placement on rank 1/rank 2 and h-file. Bishop controls dark-square escape routes (e7–h4 diagonal, f8–a3). Deliver checkmate via back-rank or …

      • llm.plan56285ms · $0.0285
      full reasoning
      Phase: endgame. Restrict White king to back-rank corner using coordinated rook placement on rank 1/rank 2 and h-file. Bishop controls dark-square escape routes (e7–h4 diagonal, f8–a3). Deliver checkmate via back-rank or suffocation pattern within 5 moves through forcing check sequences. Two-rook coordination progressively boxes White king into h1–g1–h2 triangle while bishop seals dark-square exits, forcing inevitable checkmate. Critical: opponent has zero defensive resources — king must flee toward corners, pawns provide no defense; own precision required — synchronize rook placement to block g2, g1, f2 escape routes; prevent king breakout toward center; concrete tactic — forcing checks (h-file and rank 2) drive king into tightening mating net; bishop holds guard on dark squares.
    • 6. Candidates7534 tok · 63366ms · claude-haiku-4-5 · $0.0376

      Candidates: Re2+ (Forcing check on rank 2, drives king toward corner. Leads to forced mate within 5 moves.) | Rh1+ (Check on h-file restricts king's escape. Coordinates with bishop to seal dark squares.) | Ke4 (Centraliz…

      • chess.js.legal_moves0ms
      • llm.candidates63364ms · $0.0376
      full reasoning
      Candidates: Re2+ (Forcing check on rank 2, drives king toward corner. Leads to forced mate within 5 moves.) | Rh1+ (Check on h-file restricts king's escape. Coordinates with bishop to seal dark squares.) | Ke4 (Centralizes king to support rook attack, blocks king's escape toward center.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6495 tok · 59341ms · claude-haiku-4-5 · $0.0324

      Final pick: Re2+ — Re2+ forces Kg1 or Kh1, locking White king to back rank. Rook controls rank 2 escape. Immediately threatens coordinated follow-up checks (Rg8+ or Rh8+) sealing the mating net.. Rejected: e1h1, f3e4.

      • llm.reflect59341ms · $0.0324
    • 9. Commit0 tok · 0ms

      Commit Re2+ (e1e2).

  47. 47.Kh1Sonnet663 tok · $0.0098 · 31233ms
    • 1. Observe0 tok · 1ms

      Halbzug 47, Weiss am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 2. Schach! Criticality: 0.55. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan266 tok · 11939ms · claude-sonnet-4-6 · $0.0040

      Phase: endgame. Survive the next 1-2 moves by playing the only legal move available. With Black +14 material and our king on h2 in a mating net, seek any stalemate trap or perpetual check possibility. The Philidor active…

      • llm.plan11939ms · $0.0040
      full reasoning
      Phase: endgame. Survive the next 1-2 moves by playing the only legal move available. With Black +14 material and our king on h2 in a mating net, seek any stalemate trap or perpetual check possibility. The Philidor active-rook heuristic is inapplicable — we have no rook. The opposition heuristic is irrelevant given king proximity to mate. Position is objectively lost; the sole strategic goal is to find a stalemate trick or force Black into an error — resign if no saving resource exists after exhausting legal moves. Critical: Black rook on e2 and e8 deliver mating threats; White king on h2 has minimal flight squares; Only 2 legal moves exist — g4 or h4 pawn pushes; No white rook to implement Philidor active defense; Stalemate is the only realistic saving resource if Black plays carelessly.
    • 6. Candidates233 tok · 8887ms · claude-sonnet-4-6 · $0.0035

      Candidates: Kg1 (King escapes toward center; avoids h1 corner where stalemate trap is harder to reach.) | Kh1 (Corner king maximizes stalemate chances if Black plays carelessly with Re1 or Rh8-h1.) | Kg1 (King safety fir…

      • chess.js.legal_moves0ms
      • llm.candidates8887ms · $0.0035
      full reasoning
      Candidates: Kg1 (King escapes toward center; avoids h1 corner where stalemate trap is harder to reach.) | Kh1 (Corner king maximizes stalemate chances if Black plays carelessly with Re1 or Rh8-h1.) | Kg1 (King safety first: g1 gives more flight squares than h1 corner, delaying forced mate longer.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect164 tok · 10374ms · claude-sonnet-4-6 · $0.0024

      Final pick: Kh1 — Corner maximizes stalemate trap: if Black plays Re1 or Rh1 carelessly, White is stalemated. King safety heuristic — h1 corner with pawns on g3/h3 creates a fortress-like stalemate shell.. Rejected: h2g1…

      • llm.reflect10374ms · $0.0024
      full reasoning
      Final pick: Kh1 — Corner maximizes stalemate trap: if Black plays Re1 or Rh1 carelessly, White is stalemated. King safety heuristic — h1 corner with pawns on g3/h3 creates a fortress-like stalemate shell.. Rejected: h2g1.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (h2h1).

  48. 48...Re1+Haiku13.258 tok · $0.0662 · 126772ms
    • 1. Observe0 tok · 0ms

      Halbzug 48, Schwarz am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 34. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 22ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search22ms
    • 3. Recall Opponent0 tok · 12ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search12ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan1583 tok · 19844ms · claude-haiku-4-5 · $0.0079

      Phase: endgame. Coordinate two rooks to deliver back-rank checkmate by positioning one on the first rank (forcing king into h2 corner) while the second rook controls escape squares. Bishop on f8 seals dark-square exits (…

      • llm.plan19844ms · $0.0079
      full reasoning
      Phase: endgame. Coordinate two rooks to deliver back-rank checkmate by positioning one on the first rank (forcing king into h2 corner) while the second rook controls escape squares. Bishop on f8 seals dark-square exits (e3, e7). Force checkmate within 3–4 moves. Use back-rank mating pattern with synchronized rook placement: one rook on rank 1 to cut off king escape, second rook to deliver forcing checks and prevent h-file flight, bishop to maintain dark-square control. White king suffocates into h1 corner with no defensive resources. Critical: White king has zero escape squares: h1 is current position, g1 is controlled by Black rook placement, g2/h2 become death traps once a rook reaches rank 1; Black's bishop on f8 controls e3 (dark square) permanently, blocking any sideways escape; White has five pawns only—no pieces to defend or block checks—pawn structure is frozen and useless; Black must avoid stalemate: ensure White always has a legal move (even if forced to lose immediately) until final checkmate.
    • 6. Candidates2244 tok · 25249ms · claude-haiku-4-5 · $0.0112

      Candidates: Rh2+ (Check forces Kg1, then Re1+ mates on back rank. Maintains overwhelming forcing attack.) | Re1+ (Back-rank check forces king move. Rook dominates first rank, mate unstoppable in 2-3 moves.) | Kxg3 (Captu…

      • chess.js.legal_moves0ms
      • llm.candidates25247ms · $0.0112
      full reasoning
      Candidates: Rh2+ (Check forces Kg1, then Re1+ mates on back rank. Maintains overwhelming forcing attack.) | Re1+ (Back-rank check forces king move. Rook dominates first rank, mate unstoppable in 2-3 moves.) | Kxg3 (Captures key defender, activates king. White has no pieces left, mate within 4 moves forced.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect9431 tok · 81623ms · claude-haiku-4-5 · $0.0471

      Final pick: Re1+ — Dominates first rank immediately, forcing king to move while controlling f1. Enables coordinated rook mate with h8 rook controlling escape squares on h-file. Direct back-rank pattern.. Rejected: e2h2, …

      • llm.reflect81623ms · $0.0471
      full reasoning
      Final pick: Re1+ — Dominates first rank immediately, forcing king to move while controlling f1. Enables coordinated rook mate with h8 rook controlling escape squares on h-file. Direct back-rank pattern.. Rejected: e2h2, f3g3.
    • 9. Commit0 tok · 0ms

      Commit Re1+ (e2e1).

  49. 49.Kh2Sonnet614 tok · $0.0091 · 27484ms
    • 1. Observe0 tok · 0ms

      Halbzug 49, Weiss am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 1. Schach! Criticality: 0.55. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan238 tok · 9858ms · claude-sonnet-4-6 · $0.0035

      Phase: endgame. Execute the single legal move available (check). With only 1 legal move, there is no strategic choice — play it and hope Black errs into stalemate or perpetual. No rook means Philidor/Lucena heuristics ar…

      • llm.plan9858ms · $0.0035
      full reasoning
      Phase: endgame. Execute the single legal move available (check). With only 1 legal move, there is no strategic choice — play it and hope Black errs into stalemate or perpetual. No rook means Philidor/Lucena heuristics are inapplicable per memory hits. Survive via stalemate trap: White king on h1 with no legal moves except to walk into check could yield stalemate if Black plays carelessly — this is the only saving resource in a -14 material deficit. Critical: Black rooks on e1 and e8 form mating net; White king trapped on h1/h2 corridor; Only 1 legal move exists — the check is forced; Opposition and Philidor heuristics irrelevant without own rook or pawn endgame.
    • 6. Candidates240 tok · 9564ms · claude-sonnet-4-6 · $0.0036

      Candidates: Kh2 (Only legal move. King safety first — avoid h1 mating net; stalemate trap is the sole saving resource.) | Kh2 (Forced king move; Philidor heuristics inapplicable without own rook — survive via stalemate c…

      • chess.js.legal_moves0ms
      • llm.candidates9564ms · $0.0036
      full reasoning
      Candidates: Kh2 (Only legal move. King safety first — avoid h1 mating net; stalemate trap is the sole saving resource.) | Kh2 (Forced king move; Philidor heuristics inapplicable without own rook — survive via stalemate corridor.) | Kh2 (King exits back-rank, entering h2 corridor; only practical chance is Black walking into stalemate.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect136 tok · 8033ms · claude-sonnet-4-6 · $0.0020

      Final pick: Kh2 — Only legal move. King exits h1 mating net (Re1#), entering h2 corridor. Sole saving resource is stalemate trap — Black must play precisely to convert -14 material advantage.. Rejected: h1h2.

      • llm.reflect8033ms · $0.0020
    • 9. Commit0 tok · 0ms

      Commit Kh2 (h1h2).

  50. 50...Re2+Haiku10.785 tok · $0.0539 · 217216ms
    • 1. Observe0 tok · 0ms

      Halbzug 50, Schwarz am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 36. Criticality: 0.20.

      • material-counter0ms
    • 2. Recall Position0 tok · 9ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search9ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3743 tok · 38277ms · claude-haiku-4-5 · $0.0187

      Phase: endgame. Force back-rank mate in 3–4 moves via Rh1+ (check), drive king Kg2, then Re2+ coordinates rooks for Rh1# checkmate. Exploit trapped White king. Rh1+ forces Kg2; Re2+ drives to g1 where Rh1 is mate. White …

      • llm.plan38277ms · $0.0187
      full reasoning
      Phase: endgame. Force back-rank mate in 3–4 moves via Rh1+ (check), drive king Kg2, then Re2+ coordinates rooks for Rh1# checkmate. Exploit trapped White king. Rh1+ forces Kg2; Re2+ drives to g1 where Rh1 is mate. White pawns cannot defend or promote in time. Critical: Rh1+ immediately forcing and checks; King has no escape after Kg2 + Re2+ sequence; Pawn threats irrelevant—mate comes first.
    • 6. Candidates7042 tok · 58806ms · claude-haiku-4-5 · $0.0352

      Candidates: Re2+ (Checks king along rank 2, forces Kg1 or Kh1. h8 rook ready to deliver back-rank mate.) | Rh1+ (Direct check on h2. Restricts king toward g1–g2. h8 rook remains active for follow-up tactics.) | Ke4 (Acti…

      • chess.js.legal_moves0ms
      • llm.candidates58804ms · $0.0352
      full reasoning
      Candidates: Re2+ (Checks king along rank 2, forces Kg1 or Kh1. h8 rook ready to deliver back-rank mate.) | Rh1+ (Direct check on h2. Restricts king toward g1–g2. h8 rook remains active for follow-up tactics.) | Ke4 (Activates king, supports rook assault. Improves centralization while maintaining checkmate threats.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect0 tok · 120099ms · err:Claude CLI subprocess timed out after 120000ms

      Final pick: Re2+ — Checks king along rank 2, forces Kg1 or Kh1. h8 rook ready to deliver back-rank mate.. Rejected: e1h1, f3e4. [LLM note: Claude CLI subprocess timed out after 120000ms]

    • 9. Commit0 tok · 0ms

      Commit Re2+ (e1e2).

  51. 51.Kh1Sonnet702 tok · $0.0104 · 30746ms
    • 1. Observe0 tok · 0ms

      Halbzug 51, Weiss am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 2. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 13ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search13ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan289 tok · 12920ms · claude-sonnet-4-6 · $0.0043

      Phase: endgame. Survive via stalemate trap or perpetual check. With only 2 legal moves and a -14 material deficit, the sole saving resource is forcing Black into a careless sequence that yields stalemate. Play the checki…

      • llm.plan12920ms · $0.0043
      full reasoning
      Phase: endgame. Survive via stalemate trap or perpetual check. With only 2 legal moves and a -14 material deficit, the sole saving resource is forcing Black into a careless sequence that yields stalemate. Play the checking move to keep White king in the corner corridor where stalemate becomes a threat if Black's rooks over-restrict. Stalemate is the only realistic draw — keep the White king pinned in the h1-h2 corner and hope Black's rooks accidentally leave no legal escape squares while not delivering checkmate. Critical: Black rooks on e2 and e8 form near-complete mating net; White king trapped in h1-h2 corridor with minimal escape; Memory hits: Philidor and Lucena heuristics inapplicable — no White rook exists; Opposition principle also irrelevant at -14 material; Only survival line: stalemate trap in h1 corner; any Black rook move that covers g1 and g3 simultaneously without check = stalemate.
    • 6. Candidates256 tok · 9402ms · claude-sonnet-4-6 · $0.0038

      Candidates: Kh1 (Corners the king in h1 stalemate trap; if Black's rooks over-restrict, stalemate becomes the only saving resource.) | Kg1 (Alternative corner retreat; keeps king near g1-h1 corridor where stalemate threa…

      • chess.js.legal_moves0ms
      • llm.candidates9402ms · $0.0038
      full reasoning
      Candidates: Kh1 (Corners the king in h1 stalemate trap; if Black's rooks over-restrict, stalemate becomes the only saving resource.) | Kg1 (Alternative corner retreat; keeps king near g1-h1 corridor where stalemate threats arise if Black rooks cover all escape squares carelessly.) | Kh1 (King safety first: h1 is the deepest corner, maximizing stalemate probability — the only realistic survival line at -14 material.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect157 tok · 8386ms · claude-sonnet-4-6 · $0.0023

      Final pick: Kh1 — Deepest corner maximizes stalemate trap probability. King on h1 with pawns on g3/h3 forces Black to navigate carefully — careless rook placement covering g1+h2 simultaneously creates stalemate with no l…

      • llm.reflect8386ms · $0.0023
      full reasoning
      Final pick: Kh1 — Deepest corner maximizes stalemate trap probability. King on h1 with pawns on g3/h3 forces Black to navigate carefully — careless rook placement covering g1+h2 simultaneously creates stalemate with no legal moves.. Rejected: h2g1.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (h2h1).

  52. 52...Rh2+Haiku14.230 tok · $0.0710 · 130103ms
    • 1. Observe0 tok · 0ms

      Halbzug 52, Schwarz am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 34. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3863 tok · 36794ms · claude-haiku-4-5 · $0.0193

      Phase: endgame. Exploit trapped White King on h1. Activate h-rook via Rh1+ check to force king to g2, then coordinate both rooks for forced mate. Pawn promotion secondary—mate comes first. Deliver checkmate using coordin…

      • llm.plan36794ms · $0.0193
      full reasoning
      Phase: endgame. Exploit trapped White King on h1. Activate h-rook via Rh1+ check to force king to g2, then coordinate both rooks for forced mate. Pawn promotion secondary—mate comes first. Deliver checkmate using coordinated rooks. White King has no escape; Black rooks (e2 + h8) can force mate in 4-6 moves. Critical: White King boxed on h1 with g3/h3 pawns blocking escape; Black rook on e2 is already active; h8 rook can swing to 1st rank via Rh1+ forcing check; No White defender pieces exist—pawn shield is irrelevant. Mate threat dominates all other considerations.
    • 6. Candidates4753 tok · 43512ms · claude-haiku-4-5 · $0.0237

      Candidates: Rh2+ (Forces Kg1, activates rook with check, sets up Re1+ mating pattern) | Re1+ (Back-rank check forces King escape, coordinates rooks to tighten mating net) | Kxg3 (Removes escape pawn, activates King to su…

      • chess.js.legal_moves0ms
      • llm.candidates43510ms · $0.0237
      full reasoning
      Candidates: Rh2+ (Forces Kg1, activates rook with check, sets up Re1+ mating pattern) | Re1+ (Back-rank check forces King escape, coordinates rooks to tighten mating net) | Kxg3 (Removes escape pawn, activates King to support rook mating attack, opens lines)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect5614 tok · 49777ms · claude-haiku-4-5 · $0.0280

      Final pick: Rh2+ — Rh2+ forces Kg1 only (Black King controls g2), then Re1+ delivers mate. Re1+ directly allows Kh2, weakening the mating net. Rh2+ dominates.. Rejected: e2e1, f3g3.

      • llm.reflect49777ms · $0.0280
    • 9. Commit0 tok · 0ms

      Commit Rh2+ (e2h2).

  53. 53.Kxh2Sonnet681 tok · $0.0101 · 31025ms
    • 1. Observe0 tok · 0ms

      Halbzug 53, Weiss am Zug. Phase: Endspiel. Schwarz +14 Punkte. Legale Zuege: 2. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan285 tok · 13414ms · claude-sonnet-4-6 · $0.0042

      Phase: endgame. Force stalemate by keeping the White king confined to the h1 corner. With only 2 legal moves and a -14 deficit, the sole saving resource is inducing Black to over-restrict the White king while failing to …

      • llm.plan13414ms · $0.0042
      full reasoning
      Phase: endgame. Force stalemate by keeping the White king confined to the h1 corner. With only 2 legal moves and a -14 deficit, the sole saving resource is inducing Black to over-restrict the White king while failing to deliver checkmate — creating a stalemate position. Survive via stalemate trap: play the checking move to oscillate the White king in the h1-h2 corridor, hoping Black's rooks accidentally leave zero legal squares without checkmate. Critical: Black rooks on h2 and f8 form near-complete mating net; Only 2 legal moves — any non-checking move likely accelerates mate; Stalemate requires Black rooks to cover all escape squares simultaneously without check; Memory heuristic: Philidor/Lucena rook endgame principles confirm the defender must use active rook play — irrelevant here as White has no rook, reinforcing that stalemate is the ONLY draw mechanism; Opposition heuristic confirms White king has zero active role — passive survival only.
    • 6. Candidates242 tok · 9122ms · claude-sonnet-4-6 · $0.0036

      Candidates: Kg1 (King safety first: avoid walking into rook on h2, stay on g1 to maximize stalemate trap potential.) | Kxh2 (Capture rook — only material gain available; Philidor survival principle: take what's offered, …

      • chess.js.legal_moves0ms
      • llm.candidates9122ms · $0.0036
      full reasoning
      Candidates: Kg1 (King safety first: avoid walking into rook on h2, stay on g1 to maximize stalemate trap potential.) | Kxh2 (Capture rook — only material gain available; Philidor survival principle: take what's offered, create complications.) | Kg1 (Passive king survival in corner corridor — stalemate mechanism requires oscillating h1-g1, opposition heuristic confirms passive only.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect154 tok · 8459ms · claude-sonnet-4-6 · $0.0023

      Final pick: Kxh2 — Capturing the rook on h2 is the only material gain and removes the immediate mating threat. Passive Kg1 leaves both rooks active; taking h2 eliminates one attacker and forces Black to reorganize, maxim…

      • llm.reflect8459ms · $0.0023
      full reasoning
      Final pick: Kxh2 — Capturing the rook on h2 is the only material gain and removes the immediate mating threat. Passive Kg1 leaves both rooks active; taking h2 eliminates one attacker and forces Black to reorganize, maximizing survival chances.. Rejected: h1g1.
    • 9. Commit0 tok · 0ms

      Commit Kxh2 (h1h2).

  54. 54...h5Haiku17.968 tok · $0.0897 · 167767ms
    • 1. Observe0 tok · 0ms

      Halbzug 54, Schwarz am Zug. Phase: Endspiel. Schwarz +9 Punkte. Legale Zuege: 22. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3211 tok · 32435ms · claude-haiku-4-5 · $0.0160

      Phase: endgame. Deliver check via Rh1+, force White King to g2 (only legal escape), then coordinate rook + bishop to control g1/f1/e1 escape squares for forced mate in 4–6 moves. Pawn promotion irrelevant; mate dominates…

      • llm.plan32435ms · $0.0160
      full reasoning
      Phase: endgame. Deliver check via Rh1+, force White King to g2 (only legal escape), then coordinate rook + bishop to control g1/f1/e1 escape squares for forced mate in 4–6 moves. Pawn promotion irrelevant; mate dominates. Checkmate White King by exploiting its boxed position on h2; White has zero defending pieces; rook and bishop finish the job. Critical: White King trapped on h2, blocked by own g3/h3 pawns from h-file escape; Rh1+ forces Kg2 (only legal move from check); Bishop on f8 must activate to f4/e3/d2 or e7 to cut g1 and f1 escape routes; Black rook controls mate-delivery from 1st/2nd rank after king moves to g2.
    • 6. Candidates12754 tok · 113497ms · claude-haiku-4-5 · $0.0637

      Candidates: h5 (Opens h-file for Rh1+ check; forces Kg2; initiates the planned mating attack sequence.) | Bd6 (Centralizes bishop on control square; coordinates rook + bishop to cut g1/f1 escape routes.) | Ke4 (Activates…

      • chess.js.legal_moves0ms
      • llm.candidates113496ms · $0.0637
      full reasoning
      Candidates: h5 (Opens h-file for Rh1+ check; forces Kg2; initiates the planned mating attack sequence.) | Bd6 (Centralizes bishop on control square; coordinates rook + bishop to cut g1/f1 escape routes.) | Ke4 (Activates king toward attack; controls f3 escape square; supports rook-bishop mating battery.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect2003 tok · 21799ms · claude-haiku-4-5 · $0.0100

      Final pick: h5 — Opens h-file for Rh1+ check, forcing Kg2 and initiating forced mate sequence. Most forcing continuation.. Rejected: f8d6, f3e4.

      • llm.reflect21799ms · $0.0100
    • 9. Commit0 tok · 0ms

      Commit h5 (h7h5).

  55. 55.Kg1Sonnet784 tok · $0.0117 · 33688ms
    • 1. Observe0 tok · 0ms

      Halbzug 55, Weiss am Zug. Phase: Endspiel. Schwarz +9 Punkte. Legale Zuege: 10. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan316 tok · 12386ms · claude-sonnet-4-6 · $0.0047

      Phase: endgame. Survive by avoiding immediate mate and preserving the only 2-square king corridor — oscillate between h2 and h1 hoping Black over-restricts and creates stalemate. Every move must be forced or king-preserv…

      • llm.plan12386ms · $0.0047
      full reasoning
      Phase: endgame. Survive by avoiding immediate mate and preserving the only 2-square king corridor — oscillate between h2 and h1 hoping Black over-restricts and creates stalemate. Every move must be forced or king-preserving. With a -9 material deficit and 10 legal moves, the only theoretical saving resource is stalemate: keep the White king trapped in the h1-h2 corner while hoping Black's pieces accidentally leave zero legal squares without delivering checkmate. Critical: Black king on f3 is dangerously close — one step from g2 cuts off the h-file corridor entirely; White pawns on g3/h3 are liabilities not assets — they restrict own king mobility; Philidor/Lucena heuristics from memory are irrelevant here (no White rook) — closest applicable concept is stalemate via king confinement; Opposition heuristic: Black king has total opposition advantage — White king cannot contest space; Any pawn advance (g4 or h4) changes structure but may open lines for Black bishop on f8 to join the mating net.
    • 6. Candidates245 tok · 11377ms · claude-sonnet-4-6 · $0.0036

      Candidates: Kh1 (King retreats to corner, maximizing stalemate chances by restricting own mobility — king confinement heuristic.) | Kg1 (Alternative corner square; oscillating Kh1-Kg1 is the stalemate-trap corridor with …

      • chess.js.legal_moves0ms
      • llm.candidates11377ms · $0.0036
      full reasoning
      Candidates: Kh1 (King retreats to corner, maximizing stalemate chances by restricting own mobility — king confinement heuristic.) | Kg1 (Alternative corner square; oscillating Kh1-Kg1 is the stalemate-trap corridor with Black king on f3.) | g4 (Fixes pawn structure, may restrict Black king approach via f4; heuristic suggestion aligns with pawn-structure preservation.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect223 tok · 9896ms · claude-sonnet-4-6 · $0.0033

      Final pick: Kg1 — Kg1 keeps both h1 and f1 as oscillation squares, maximizing the stalemate corridor. Black king on f3 means Kh1 immediately allows Kg2# or Kf2 sealing the corner — Kg1 preserves one extra escape square..…

      • llm.reflect9896ms · $0.0033
      full reasoning
      Final pick: Kg1 — Kg1 keeps both h1 and f1 as oscillation squares, maximizing the stalemate corridor. Black king on f3 means Kh1 immediately allows Kg2# or Kf2 sealing the corner — Kg1 preserves one extra escape square.. Rejected: h2h1, g3g4.
    • 9. Commit0 tok · 0ms

      Commit Kg1 (h2g1).

  56. 56...Kxg3Haiku22.132 tok · $0.1106 · 178022ms
    • 1. Observe0 tok · 0ms

      Halbzug 56, Schwarz am Zug. Phase: Endspiel. Schwarz +9 Punkte. Legale Zuege: 23. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan7764 tok · 62435ms · claude-haiku-4-5 · $0.0388

      Phase: endgame. Systematically coordinate R+B to checkmate White King trapped on g1/h2. Rook controls ranks/files, Bishop seals diagonals, King supports attack. Exploit White's hemmed-in position. Force White King to h2 …

      • llm.plan62435ms · $0.0388
      full reasoning
      Phase: endgame. Systematically coordinate R+B to checkmate White King trapped on g1/h2. Rook controls ranks/files, Bishop seals diagonals, King supports attack. Exploit White's hemmed-in position. Force White King to h2 (only escape after Rook checks), then activate Bishop via e7→d6→c5 or similar to cut f1/e2/d3 escape routes. Deliver mate via back-rank Rook or lateral King+Bishop maneuver. Critical: White King boxed by own pawns g3, h3; confined to g1-h2 pocket; Black King on f3 controls critical squares f2, g2, g3; supports mating net; Bishop on f8 (dark squares) must activate to seal f1, e2, d3 diagonals; currently inactive; Rook needs rank/file control to prevent Kg1 escape after King moves to h2; White queenside pawns (a2, b2, c2) are slow stalls; King safety dominates; no mating counterplay.
    • 6. Candidates10074 tok · 76783ms · claude-haiku-4-5 · $0.0503

      Candidates: Kxg3 (King advances and removes pawn. Traps White King to f1, h1, or h2. Activates King in mating attack.) | Bc5+ (Bishop activates on long diagonal with check. Forces King move. Seals critical escape squares…

      • chess.js.legal_moves0ms
      • llm.candidates76782ms · $0.0503
      full reasoning
      Candidates: Kxg3 (King advances and removes pawn. Traps White King to f1, h1, or h2. Activates King in mating attack.) | Bc5+ (Bishop activates on long diagonal with check. Forces King move. Seals critical escape squares.) | Ke4 (King centralizes toward kingside, coordinates with Rook and Bishop for final mating assault.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4294 tok · 38775ms · claude-haiku-4-5 · $0.0214

      Final pick: Kxg3 — Traps White King immediately. After Kf1, Rh1+ forces mate. If Kh1, Bc5 seals all escape routes.. Rejected: f8c5, f3e4.

      • llm.reflect38775ms · $0.0214
    • 9. Commit0 tok · 0ms

      Commit Kxg3 (f3g3).

  57. 57.Kh1Sonnet844 tok · $0.0126 · 32307ms
    • 1. Observe0 tok · 0ms

      Halbzug 57, Weiss am Zug. Phase: Endspiel. Schwarz +10 Punkte. Legale Zuege: 9. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 21ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search21ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan394 tok · 13969ms · claude-sonnet-4-6 · $0.0059

      Phase: endgame. Survive by oscillating the White king between g1 and h1/h2 to preserve the corner stalemate trap. The h3-pawn and g1-king must stay passive — any active move risks self-destroying the stalemate cage. With…

      • llm.plan13969ms · $0.0059
      full reasoning
      Phase: endgame. Survive by oscillating the White king between g1 and h1/h2 to preserve the corner stalemate trap. The h3-pawn and g1-king must stay passive — any active move risks self-destroying the stalemate cage. With Black king on g3, the cage is nearly set: if Black overruns without leaving a legal escape, stalemate is the only draw resource. Engineer stalemate by keeping the White king in the h1-g1 corridor behind the h3-pawn, forcing Black to either overshoot (no legal White moves = stalemate) or allow perpetual oscillation. Critical: Black king on g3 is one step from h2 — if it lands on h2, White king is mated on g1 with no flight squares; The h3-pawn is a double-edged liability: it blocks the Black king from h3 (good) but also restricts White king mobility (bad); Memory heuristic ENDGAME opposition: White has no useful opposition to claim — king is purely passive, stalemate geometry is the only plan; Memory heuristic ENDGAME philidor/lucena: irrelevant here (no rook), but the underlying principle — passive defense in the corner — applies directly; With only 9 legal moves and -10 material, every White reply must avoid giving Black a clean mating net while preserving at least one legal move on the next ply.
    • 6. Candidates246 tok · 9901ms · claude-sonnet-4-6 · $0.0037

      Candidates: Kh1 (Passive king oscillation in h1-g1 corridor preserves stalemate cage; avoids Kf1 which opens flight squares.) | Kf1 (Alternative oscillation square; keeps king passive per endgame corner-defense principle…

      • chess.js.legal_moves0ms
      • llm.candidates9900ms · $0.0037
      full reasoning
      Candidates: Kh1 (Passive king oscillation in h1-g1 corridor preserves stalemate cage; avoids Kf1 which opens flight squares.) | Kf1 (Alternative oscillation square; keeps king passive per endgame corner-defense principle, away from Black king on g3.) | h4 (Advances h-pawn to reduce Black king h2-landing threat; changes cage geometry but risks losing stalemate barrier.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect204 tok · 8395ms · claude-sonnet-4-6 · $0.0030

      Final pick: Kh1 — Passive oscillation in h1-g1 corridor preserves stalemate cage. Black king on g3 cannot reach h2 without triggering stalemate — h3-pawn blocks h3, Kh1 keeps the corner geometry intact.. Rejected: g1f1, …

      • llm.reflect8395ms · $0.0030
      full reasoning
      Final pick: Kh1 — Passive oscillation in h1-g1 corridor preserves stalemate cage. Black king on g3 cannot reach h2 without triggering stalemate — h3-pawn blocks h3, Kh1 keeps the corner geometry intact.. Rejected: g1f1, h3h4.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (g1h1).

  58. 58...Kxh3Haiku16.797 tok · $0.0839 · 144841ms
    • 1. Observe0 tok · 0ms

      Halbzug 58, Schwarz am Zug. Phase: Endspiel. Schwarz +10 Punkte. Legale Zuege: 24. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 19ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search19ms
    • 3. Recall Opponent0 tok · 14ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search14ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan5562 tok · 44251ms · claude-haiku-4-5 · $0.0278

      Phase: endgame. Deliver checkmate within 5 moves. Execute Rh2+ to drive White King to h2, activate Bishop to control f1 and e2, seal White King's escape squares, then deliver mate with coordinated R+B+K attack. Systemati…

      • llm.plan44251ms · $0.0278
      full reasoning
      Phase: endgame. Deliver checkmate within 5 moves. Execute Rh2+ to drive White King to h2, activate Bishop to control f1 and e2, seal White King's escape squares, then deliver mate with coordinated R+B+K attack. Systematically restrict White King's mobility with Rook checks while activating Bishop to control critical dark squares, then deliver checkmate with coordinated R+B+K. Critical: White King trapped on h1, hemmed by own h3 pawn and Black King on g3—no legal moves except to h2 after Rook check; Bishop on f8 is still dormant—must activate immediately to f7-e6-d5 path to control f1 and e2 escape squares; Rook checks on h-file (Rh2+) and potential back-rank tactics; White has zero counterplay and no defensive resources.
    • 6. Candidates4615 tok · 42272ms · claude-haiku-4-5 · $0.0230

      Candidates: Kxh3 (Captures pawn, removes defender. Enables Rh1# next move—White King trapped (h2, g2 by Kh3; g1 by Rook). Mate in 2 moves.) | Be7 (Activates Bishop toward critical dark squares f1/e2. Begins restricting W…

      • chess.js.legal_moves0ms
      • llm.candidates42271ms · $0.0230
      full reasoning
      Candidates: Kxh3 (Captures pawn, removes defender. Enables Rh1# next move—White King trapped (h2, g2 by Kh3; g1 by Rook). Mate in 2 moves.) | Be7 (Activates Bishop toward critical dark squares f1/e2. Begins restricting White King escape routes. Supports multi-move mating attack.) | Bd6 (Develops Bishop from dormancy. Centralizes on dark-square diagonal. Flexible positioning for coordinated R+B attack against hemmed King.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6620 tok · 58274ms · claude-haiku-4-5 · $0.0331

      Final pick: Kxh3 — Captures h3 pawn, King dominates h3 controlling g2/h2 escape squares. Forces White King to g1, then Rook delivers mate on h-file or g-file within 2 moves.. Rejected: f8e7, f8d6.

      • llm.reflect58274ms · $0.0331
    • 9. Commit0 tok · 0ms

      Commit Kxh3 (g3h3).

  59. 59.Kg1Sonnet676 tok · $0.0100 · 27713ms
    • 1. Observe0 tok · 1ms

      Halbzug 59, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 7. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 8ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search8ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan251 tok · 10865ms · claude-sonnet-4-6 · $0.0037

      Phase: endgame. Maintain the stalemate cage: keep the White king oscillating in the h1-g1 corridor, never voluntarily leave the corner. With Black +11 material, the only realistic draw resource is stalemate — Black king …

      • llm.plan10865ms · $0.0037
      full reasoning
      Phase: endgame. Maintain the stalemate cage: keep the White king oscillating in the h1-g1 corridor, never voluntarily leave the corner. With Black +11 material, the only realistic draw resource is stalemate — Black king on h3, White king trapped with no legal moves. Force stalemate by staying passive in the h1 corner, letting Black's overwhelming material advantage become a liability if Black overruns without leaving White a legal escape square. Critical: Black king on h3 is already on the stalemate square — one misstep by White moving off h1/g1 corridor destroys the cage; Opposition heuristic confirms: staying passive and letting Black have the move is correct — do not fight for space; No legal White move should advance pawns or leave h1 voluntarily — passive king oscillation is the only plan.
    • 6. Candidates243 tok · 8421ms · claude-sonnet-4-6 · $0.0036

      Candidates: Kg1 (King oscillation in h1-g1 corridor maintains stalemate cage; passive king is the only draw resource with Black king on h3.) | a3 (Passive pawn move delays material advance; opposition heuristic confirms …

      • chess.js.legal_moves0ms
      • llm.candidates8421ms · $0.0036
      full reasoning
      Candidates: Kg1 (King oscillation in h1-g1 corridor maintains stalemate cage; passive king is the only draw resource with Black king on h3.) | a3 (Passive pawn move delays material advance; opposition heuristic confirms staying passive lets Black's overwhelming material become liability.) | b3 (Passive flank pawn move; avoids king leaving corner, preserving stalemate cage structure with Black king already on h3.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect182 tok · 8402ms · claude-sonnet-4-6 · $0.0027

      Final pick: Kg1 — King oscillation in h1-g1 corridor is the only draw resource. Pawn moves (a3/b3) permanently reduce future stalemate configurations and give Black a tempo; passive king cycling preserves the cage with B…

      • llm.reflect8402ms · $0.0027
      full reasoning
      Final pick: Kg1 — King oscillation in h1-g1 corridor is the only draw resource. Pawn moves (a3/b3) permanently reduce future stalemate configurations and give Black a tempo; passive king cycling preserves the cage with Black king already on h3.. Rejected: a2a3, b2b3.
    • 9. Commit0 tok · 0ms

      Commit Kg1 (h1g1).

  60. 60...Bc5+Haiku12.942 tok · $0.0646 · 119031ms
    • 1. Observe0 tok · 0ms

      Halbzug 60, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 22. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 4ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search4ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan1904 tok · 21469ms · claude-haiku-4-5 · $0.0095

      Phase: endgame. Execute Rh2+ to force White King away from g1. Activate dormant Bishop via d5 or e6 to control f1, e2. Coordinate R+B+K to systematically trap White King and deliver mate within 5 moves. Exploit overwhelm…

      • llm.plan21469ms · $0.0095
      full reasoning
      Phase: endgame. Execute Rh2+ to force White King away from g1. Activate dormant Bishop via d5 or e6 to control f1, e2. Coordinate R+B+K to systematically trap White King and deliver mate within 5 moves. Exploit overwhelming material advantage (R+B+5 pawns vs 3 pawns) to squeeze White King into a mating net via coordinated Rook checks, Bishop control of key dark squares, and King support. Critical: White King on g1 lacks escape routes once h1 sealed by Rook; Black King on h3 already active near White King—must coordinate with R+B; Bishop on f8 is critical tempo loss if not activated within 2 moves; Forced sequence: Rh2+ (King Kf1 or Kf2), then Be6/d5 to cut f1, then mating attack.
    • 6. Candidates8265 tok · 68784ms · claude-haiku-4-5 · $0.0413

      Candidates: Bc5+ (Gives check, forces White King away from g1, activates dormant Bishop with tempo) | Bd6 (Centralizes Bishop, controls g3/h2 near White King, supports mating net formation) | Be7 (Develops Bishop flexibl…

      • chess.js.legal_moves0ms
      • llm.candidates68782ms · $0.0413
      full reasoning
      Candidates: Bc5+ (Gives check, forces White King away from g1, activates dormant Bishop with tempo) | Bd6 (Centralizes Bishop, controls g3/h2 near White King, supports mating net formation) | Be7 (Develops Bishop flexibly, maintains attack options, prepares to support coordinated assault)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect2773 tok · 28750ms · claude-haiku-4-5 · $0.0138

      Final pick: Bc5+ — Bc5+ gives check, forces White King away with tempo, activates dormant Bishop controlling critical e3-f2-g1 diagonal, accelerates mating attack decisively.. Rejected: f8d6, f8e7.

      • llm.reflect28750ms · $0.0138
    • 9. Commit0 tok · 0ms

      Commit Bc5+ (f8c5).

  61. 61.Kh1Sonnet710 tok · $0.0105 · 29524ms
    • 1. Observe0 tok · 0ms

      Halbzug 61, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 2. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 20ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search20ms
    • 3. Recall Opponent0 tok · 13ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search13ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan292 tok · 12410ms · claude-sonnet-4-6 · $0.0043

      Phase: endgame. Maintain the stalemate cage by keeping the White king in the g1-h1 corridor. With only 2 legal moves available and the Black king already on h3, any deviation from this corridor destroys the only draw res…

      • llm.plan12410ms · $0.0043
      full reasoning
      Phase: endgame. Maintain the stalemate cage by keeping the White king in the g1-h1 corridor. With only 2 legal moves available and the Black king already on h3, any deviation from this corridor destroys the only draw resource. Oscillate passively between g1 and h1. Force stalemate by staying in the corner — Black's +11 material advantage becomes irrelevant if Black cannot avoid trapping White without leaving escape squares. Critical: Only 2 legal moves — both must stay within the stalemate corridor; Opposition heuristic (memory hit): king placement is everything here — opposition principles confirm that staying on g1/h1 denies Black the key tempo needed to avoid stalemate; Black king on h3 is already the stalemate anchor square — do not give it a reason to move away by playing actively; Philidor/Lucena rook heuristics (memory hits) are not directly applicable but confirm: passive defense in the corner is correct defensive technique in hopeless material positions.
    • 6. Candidates257 tok · 9073ms · claude-sonnet-4-6 · $0.0038

      Candidates: Kh1 (Stays in stalemate corridor g1-h1; Black king on h3 anchors the stalemate trap — king safety first, corner is only draw resource.) | Kf1 (Only alternative legal move; exits corridor but keeps passive def…

      • chess.js.legal_moves0ms
      • llm.candidates9073ms · $0.0038
      full reasoning
      Candidates: Kh1 (Stays in stalemate corridor g1-h1; Black king on h3 anchors the stalemate trap — king safety first, corner is only draw resource.) | Kf1 (Only alternative legal move; exits corridor but keeps passive defense — opposition principle confirms corner oscillation is correct technique.) | Kh1 (Repetition of Kh1 enforces stalemate corridor discipline; with only 2 legal moves, passive king placement is the sole drawing resource.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect161 tok · 7988ms · claude-sonnet-4-6 · $0.0024

      Final pick: Kh1 — Stays in the g1-h1 stalemate corridor. Black king on h3 anchors the trap — any deviation gives Black tempo to reorganize and avoid stalemate. Corner oscillation is the only draw resource with +11 materi…

      • llm.reflect7987ms · $0.0024
      full reasoning
      Final pick: Kh1 — Stays in the g1-h1 stalemate corridor. Black king on h3 anchors the trap — any deviation gives Black tempo to reorganize and avoid stalemate. Corner oscillation is the only draw resource with +11 material deficit.. Rejected: g1f1.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (g1h1).

  62. 62...Kg4Haiku9.451 tok · $0.0471 · 92922ms
    • 1. Observe0 tok · 0ms

      Halbzug 62, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 32. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 9ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search9ms
    • 3. Recall Opponent0 tok · 10ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search10ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2195 tok · 23264ms · claude-haiku-4-5 · $0.0109

      Phase: endgame. Force Kh1 to g1 via Rh2+ check. Activate Bc5 to dark squares (d5, e6) controlling flight squares f1, e2. Coordinate R+B+K to construct unstoppable mating net. Checkmate within 5 moves. Exploit R+B+5p vers…

      • llm.plan23264ms · $0.0109
      full reasoning
      Phase: endgame. Force Kh1 to g1 via Rh2+ check. Activate Bc5 to dark squares (d5, e6) controlling flight squares f1, e2. Coordinate R+B+K to construct unstoppable mating net. Checkmate within 5 moves. Exploit R+B+5p versus 3p material advantage to trap White King via forcing checks and dark-square domination, delivering mate. Critical: White King h1 trapped: after Rh2+ Kg1 forced, h1 sealed by Rook; no escape; Bishop c5 currently passive: must activate immediately to d5/e6 to control f1, e2, cut off king flight squares; Black King h3 ideally placed: already attacking zone, ready to support final mating phase.
    • 6. Candidates3363 tok · 33760ms · claude-haiku-4-5 · $0.0168

      Candidates: Bd4 (Activates bishop to dark-square control (e3, f2), sealing king flight squares for mating net construction.) | Kg4 (Clears h-file blockade. Enables Rh2+ forcing check next move; advances king into attack …

      • chess.js.legal_moves0ms
      • llm.candidates33757ms · $0.0168
      full reasoning
      Candidates: Bd4 (Activates bishop to dark-square control (e3, f2), sealing king flight squares for mating net construction.) | Kg4 (Clears h-file blockade. Enables Rh2+ forcing check next move; advances king into attack zone.) | Kg3 (Alternative h-file clearance. Maintains central presence while preparing forcing-check sequence and king support.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect3893 tok · 35865ms · claude-haiku-4-5 · $0.0194

      Final pick: Kg4 — Clears h-file to enable forcing Rh2+ check next move. King advances into attack zone supporting final mating coordination. Maintains forcing tempo critical for 5-move mate.. Rejected: c5d4, h3g3.

      • llm.reflect35865ms · $0.0194
    • 9. Commit0 tok · 0ms

      Commit Kg4 (h3g4).

  63. 63.Kg2Sonnet767 tok · $0.0114 · 32758ms
    • 1. Observe0 tok · 0ms

      Halbzug 63, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 8. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan286 tok · 13416ms · claude-sonnet-4-6 · $0.0043

      Phase: endgame. Survive via stalemate trap — oscillate White king between g1 and h1, force Black into a position where any winning attempt stalemates White. With only pawns vs pawns and a bishop, Black's +11 advantage is…

      • llm.plan13416ms · $0.0043
      full reasoning
      Phase: endgame. Survive via stalemate trap — oscillate White king between g1 and h1, force Black into a position where any winning attempt stalemates White. With only pawns vs pawns and a bishop, Black's +11 advantage is irrelevant if the cage holds. Accept the material deficit as permanent and pursue the only theoretical draw resource: keep the White king confined to the corner stalemate zone, denying Black a clean winning path without stalemating. Critical: Memory hit (opposition): king placement is everything — corner confinement is the draw resource; Memory hit (endgame opposition): the non-moving king holds the key square — stay passive, let Black come to us; Black bishop on c5 controls key diagonals; White must not walk into bishop check while fleeing the corner; 8 legal moves now (up from 2) — re-evaluate whether stalemate corridor is still the right approach or if active resistance is possible; Black king on g4 is aggressive — any White king move must avoid walking into zugzwang.
    • 6. Candidates268 tok · 8916ms · claude-sonnet-4-6 · $0.0040

      Candidates: Kg2 (Memory hit (opposition): king placement is everything — step out of corner to avoid immediate stalemate while keeping g1/h1 corridor accessible.) | a3 (Pawn advances create zugzwang resistance; memory hi…

      • chess.js.legal_moves0ms
      • llm.candidates8916ms · $0.0040
      full reasoning
      Candidates: Kg2 (Memory hit (opposition): king placement is everything — step out of corner to avoid immediate stalemate while keeping g1/h1 corridor accessible.) | a3 (Pawn advances create zugzwang resistance; memory hit (endgame opposition): passive king holds key square, so pawn moves buy tempo in the stalemate corridor.) | Kh2 (Oscillate king between h1 and h2 — corner confinement draw resource; avoids bishop check from c5 diagonal while denying Black a clean winning path.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect213 tok · 10394ms · claude-sonnet-4-6 · $0.0032

      Final pick: Kg2 — Step out of corner to retain mobility; g2 avoids immediate stalemate while keeping h1/g1 corridor accessible. Memory hit (opposition): king placement is everything — g2 contests more squares than h2, re…

      • llm.reflect10394ms · $0.0032
      full reasoning
      Final pick: Kg2 — Step out of corner to retain mobility; g2 avoids immediate stalemate while keeping h1/g1 corridor accessible. Memory hit (opposition): king placement is everything — g2 contests more squares than h2, resisting Black king on g4 advancing to f3.. Rejected: a2a3, h1h2.
    • 9. Commit0 tok · 0ms

      Commit Kg2 (h1g2).

  64. 64...Bd4Haiku18.901 tok · $0.0944 · 166365ms
    • 1. Observe0 tok · 0ms

      Halbzug 64, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 33. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 20ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search20ms
    • 3. Recall Opponent0 tok · 13ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search13ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan4256 tok · 40230ms · claude-haiku-4-5 · $0.0212

      Phase: endgame. Deliver forcing checks to drive White king into corner. Activate bishop to seal dark-square escape routes. Construct mating net within five moves. Checkmate via Black's material advantage and White king e…

      • llm.plan40230ms · $0.0212
      full reasoning
      Phase: endgame. Deliver forcing checks to drive White king into corner. Activate bishop to seal dark-square escape routes. Construct mating net within five moves. Checkmate via Black's material advantage and White king exposure; mate is forced within five moves. Critical: White king escape squares must be systematically eliminated via forcing checks and bishop control; Bishop on c5 is currently passive—must activate immediately to control critical escape squares; Black king is ideally positioned; maintain piece coordination to prevent any king escape.
    • 6. Candidates8556 tok · 74307ms · claude-haiku-4-5 · $0.0427

      Candidates: Bd4 (Centralizes bishop to control escape squares, seals dark-square routes, prepares mating net.) | Rh7 (Activates rook toward White king; prepares forcing checks from seventh rank.) | Rh6 (Positions rook on…

      • chess.js.legal_moves0ms
      • llm.candidates74305ms · $0.0427
      full reasoning
      Candidates: Bd4 (Centralizes bishop to control escape squares, seals dark-square routes, prepares mating net.) | Rh7 (Activates rook toward White king; prepares forcing checks from seventh rank.) | Rh6 (Positions rook on sixth rank to deliver checks and drive king toward corner.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6089 tok · 51775ms · claude-haiku-4-5 · $0.0304

      Final pick: Bd4 — Activates passive bishop to control g1, e3, f2—critical escape squares. Centralizes piece and constructs mating net base immediately per plan.. Rejected: h8h7, h8h6.

      • llm.reflect51775ms · $0.0304
    • 9. Commit0 tok · 0ms

      Commit Bd4 (c5d4).

  65. 65.Kh1Sonnet797 tok · $0.0118 · 32439ms
    • 1. Observe0 tok · 0ms

      Halbzug 65, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 9. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan312 tok · 11987ms · claude-sonnet-4-6 · $0.0046

      Phase: endgame. Survive via stalemate trap — oscillate White king between g1/h1/f1 corner zone, deny Black a clean winning path without stalemating. Accept permanent material deficit as the only theoretical draw resource…

      • llm.plan11987ms · $0.0046
      full reasoning
      Phase: endgame. Survive via stalemate trap — oscillate White king between g1/h1/f1 corner zone, deny Black a clean winning path without stalemating. Accept permanent material deficit as the only theoretical draw resource. Force stalemate by keeping White king confined to the back-rank corner, making any Black winning attempt self-defeating through stalemate. Critical: Memory hit (endgame opposition): king placement is everything — corner confinement is the only draw resource; Memory hit (endgame philidor/lucena): no rook on board, so standard rook-endgame technique irrelevant — stalemate cage is the only parallel principle applicable; Black king on g4 with bishop d4 is well-coordinated but must avoid stalemating White; White has 9 legal moves — must choose the one that tightens the stalemate cage most, likely retreating king toward h1 or f1 corner; Black pawns on a7/b7/c7/f7/g7/h5 are not immediate threats — stalemate defense has time.
    • 6. Candidates247 tok · 10445ms · claude-sonnet-4-6 · $0.0037

      Candidates: Kh1 (Corner confinement tightens stalemate cage; king on h1 maximizes stalemate trap potential against Black's coordinated bishop+king.) | Kf1 (Back-rank corner zone — king oscillation f1/h1 denies Black clea…

      • chess.js.legal_moves0ms
      • llm.candidates10445ms · $0.0037
      full reasoning
      Candidates: Kh1 (Corner confinement tightens stalemate cage; king on h1 maximizes stalemate trap potential against Black's coordinated bishop+king.) | Kf1 (Back-rank corner zone — king oscillation f1/h1 denies Black clean winning path, stalemate opposition principle.) | Kh2 (Transitional king move toward h1 corner; maintains stalemate cage while avoiding bishop check exposure.)
    • 7. Verify0 tok · 2ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect238 tok · 9963ms · claude-sonnet-4-6 · $0.0035

      Final pick: Kh1 — Kh1 is the deepest corner confinement — king on h1 with pawns on a2/b2/c2 creates maximum stalemate trap. Black bishop on d4 and king on g4 must avoid g3 Kh1 stalemate. Corner king is hardest to dislodg…

      • llm.reflect9963ms · $0.0035
      full reasoning
      Final pick: Kh1 — Kh1 is the deepest corner confinement — king on h1 with pawns on a2/b2/c2 creates maximum stalemate trap. Black bishop on d4 and king on g4 must avoid g3 Kh1 stalemate. Corner king is hardest to dislodge cleanly.. Rejected: g2f1, g2h2.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (g2h1).

  66. 66...Bf2Haiku29.935 tok · $0.1496 · 243823ms
    • 1. Observe0 tok · 0ms

      Halbzug 66, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 36. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan9986 tok · 80498ms · claude-haiku-4-5 · $0.0499

      Phase: endgame. Force mate within three moves via Rh1+ (driving Kg1), Bf2+ check (exploiting Black king on g4 to control f3), then coordinate rook and bishop to seal escape and deliver checkmate. Absolute victory through…

      • llm.plan80498ms · $0.0499
      full reasoning
      Phase: endgame. Force mate within three moves via Rh1+ (driving Kg1), Bf2+ check (exploiting Black king on g4 to control f3), then coordinate rook and bishop to seal escape and deliver checkmate. Absolute victory through material dominance and king confinement. Drive White king from h1→g1 via rook check, activate bishop to seal f-file escape, use Black king's territorial control (f3, g3, g5) to enforce mating net. Critical: Rh1+ is purely forcing—White has only Kg1; Black king on g4 strategically controls f3, g3, g5—critical mating squares; Bishop must immediately activate from d4 (e.g., Bf2+ giving check) to cut White king escape routes; Rook dominates h-file; bishop must seal f-file; coordination delivers mate within three moves.
    • 6. Candidates7959 tok · 63759ms · claude-haiku-4-5 · $0.0398

      Candidates: h4 (Opens h-file for rook, threatens Rh1+ next move, drives king toward mate) | Bf2 (Activates bishop toward kingside, controls g1/h2 escape squares, prepares mating net) | Kg3 (King invades kingside, control…

      • chess.js.legal_moves0ms
      • llm.candidates63757ms · $0.0398
      full reasoning
      Candidates: h4 (Opens h-file for rook, threatens Rh1+ next move, drives king toward mate) | Bf2 (Activates bishop toward kingside, controls g1/h2 escape squares, prepares mating net) | Kg3 (King invades kingside, controls f3/h2/h3, coordinates with rook/bishop for mate)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect11990 tok · 99545ms · claude-haiku-4-5 · $0.0599

      Final pick: Bf2 — Activates bishop to control g1, g3, restricts White king escape. Bf2 forces Kg2 or Kh2, then Kg3 drives king into mating net. Immediately forcing.. Rejected: h5h4, g4g3.

      • llm.reflect99545ms · $0.0599
    • 9. Commit0 tok · 0ms

      Commit Bf2 (d4f2).

  67. 67.Kg2Sonnet804 tok · $0.0120 · 32727ms
    • 1. Observe0 tok · 0ms

      Halbzug 67, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 8. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan365 tok · 13914ms · claude-sonnet-4-6 · $0.0054

      Phase: endgame. Confine White king to h1 corner, forcing stalemate threat on every Black winning attempt. With only 8 legal moves and Black bishop on f2, oscillate between h1 and g1 to maintain the stalemate cage. Any Bl…

      • llm.plan13914ms · $0.0054
      full reasoning
      Phase: endgame. Confine White king to h1 corner, forcing stalemate threat on every Black winning attempt. With only 8 legal moves and Black bishop on f2, oscillate between h1 and g1 to maintain the stalemate cage. Any Black king advance risks trapping White with no legal moves. Survive via stalemate — the only theoretical drawing resource in a -11 material deficit is keeping the White king locked in the h1/g1 corner so Black cannot deliver checkmate without producing stalemate. Critical: Black bishop f2 already controls g1 — White king on h1 has severely limited mobility, stalemate threshold is near; Memory hit (endgame opposition): king placement is everything — corner confinement is the only draw resource; oscillate h1-g1 without overstepping; Memory hit (endgame philidor/lucena): no rook on board, standard rook technique irrelevant — pure king-and-pawn stalemate cage logic applies; Black king on g4 is approaching — if White plays passively to h1, Black must advance carefully or gift stalemate; 8 legal moves means White is not yet stalemated — maintain that razor-thin margin by choosing moves that keep legal options alive while baiting Black into a stalemate trap.
    • 6. Candidates245 tok · 9393ms · claude-sonnet-4-6 · $0.0036

      Candidates: Kh2 (King stays in corner zone; bishop f2 controls g1, so h2 avoids immediate stalemate while keeping cage intact.) | Kg2 (Step toward center; endgame opposition principle — king activity preserves legal move…

      • chess.js.legal_moves0ms
      • llm.candidates9393ms · $0.0036
      full reasoning
      Candidates: Kh2 (King stays in corner zone; bishop f2 controls g1, so h2 avoids immediate stalemate while keeping cage intact.) | Kg2 (Step toward center; endgame opposition principle — king activity preserves legal moves, avoids instant stalemate on h1.) | a3 (Pawn move maintains legal options; stalemate cage logic — keeping moves alive is the only drawing resource at -11 material.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect194 tok · 9393ms · claude-sonnet-4-6 · $0.0029

      Final pick: Kg2 — Bishop f2 controls g1 AND h4; Kg2 escapes the h1 corner, preserving more legal king moves and avoiding immediate stalemate. Endgame opposition: king activity is the only drawing resource at -11.. Reject…

      • llm.reflect9393ms · $0.0029
      full reasoning
      Final pick: Kg2 — Bishop f2 controls g1 AND h4; Kg2 escapes the h1 corner, preserving more legal king moves and avoiding immediate stalemate. Endgame opposition: king activity is the only drawing resource at -11.. Rejected: h1h2, a2a3.
    • 9. Commit0 tok · 0ms

      Commit Kg2 (h1g2).

  68. 68...Be3Haiku18.178 tok · $0.0908 · 154689ms
    • 1. Observe0 tok · 0ms

      Halbzug 68, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 32. Criticality: 0.00.

      • material-counter0ms
    • 2. Recall Position0 tok · 6ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search6ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan4583 tok · 44786ms · claude-haiku-4-5 · $0.0229

      Phase: endgame. Play Rh2+ forcing White king from g2. Activate bishop (Be3 or Be1) to deliver follow-up check and seal escape routes. Mate in 2–3 moves via coordinated R+B. Confine White king using forcing rook checks. B…

      • llm.plan44786ms · $0.0229
      full reasoning
      Phase: endgame. Play Rh2+ forcing White king from g2. Activate bishop (Be3 or Be1) to deliver follow-up check and seal escape routes. Mate in 2–3 moves via coordinated R+B. Confine White king using forcing rook checks. Black king (g4) controls f3, g3, g5. Bishop pivots to deliver mating blow. No White defense exists. Critical: Rh2+ is forcing; White king has limited shelter; Follow-up bishop move (e3, e1, g1) cuts off escape; Black king strategically placed blocking critical squares; Material dominance guarantees mate within three moves.
    • 6. Candidates7756 tok · 66420ms · claude-haiku-4-5 · $0.0387

      Candidates: Be3 (Activates bishop on long diagonal, directly supporting mating attack. Controls g1 and critical escape squares.) | Rh7 (Brings rook toward the attack, prepares eventual Rh2. Coordinates R+B mating net aro…

      • chess.js.legal_moves0ms
      • llm.candidates66417ms · $0.0387
      full reasoning
      Candidates: Be3 (Activates bishop on long diagonal, directly supporting mating attack. Controls g1 and critical escape squares.) | Rh7 (Brings rook toward the attack, prepares eventual Rh2. Coordinates R+B mating net around cornered White king.) | Bd4 (Centralizes bishop, controls key diagonals. Flexible piece placement supporting multi-move mating themes via R+B coordination.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect5839 tok · 43460ms · claude-haiku-4-5 · $0.0292

      Final pick: Be3 — Activates bishop on key diagonal controlling g1, f4. Immediately seals White king escape routes. Threatens Rh2+ forcing mate: Kh1 Rh2#; Kh3 Rh2# (h5 pawn blocks); Kf1 Rh2 with unstoppable mate threat.. …

      • llm.reflect43460ms · $0.0292
      full reasoning
      Final pick: Be3 — Activates bishop on key diagonal controlling g1, f4. Immediately seals White king escape routes. Threatens Rh2+ forcing mate: Kh1 Rh2#; Kh3 Rh2# (h5 pawn blocks); Kf1 Rh2 with unstoppable mate threat.. Rejected: h8h7, f2d4.
    • 9. Commit0 tok · 0ms

      Commit Be3 (f2e3).

  69. 69.Kh2Sonnet730 tok · $0.0108 · 37145ms
    • 1. Observe0 tok · 0ms

      Halbzug 69, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 9. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 13ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search13ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan272 tok · 18282ms · claude-sonnet-4-6 · $0.0040

      Phase: endgame. Oscillate White king between g2 and h2/h1 to maintain stalemate cage. Black bishop on e3 controls f2/g1 — any Black king approach toward g3 risks stalemate. Survive via perpetual king oscillation in the g…

      • llm.plan18282ms · $0.0040
      full reasoning
      Phase: endgame. Oscillate White king between g2 and h2/h1 to maintain stalemate cage. Black bishop on e3 controls f2/g1 — any Black king approach toward g3 risks stalemate. Survive via perpetual king oscillation in the g2/h2 box, denying Black a clean mating net without producing stalemate. With -11 material and only pawns vs bishop+pawns, the sole drawing resource is the stalemate trap: keep the White king in the h1/g2 corner so Black cannot advance without gifting stalemate. Critical: Black bishop e3 controls f2/d2/g1 — White king on g2 is nearly stalemated already; Opposition heuristic: Black king on g4 approaching g3 triggers stalemate if White has no legal pawn moves; White a/b/c pawns are the only legal alternatives — advancing them burns tempos but extends survival.
    • 6. Candidates262 tok · 10422ms · claude-sonnet-4-6 · $0.0039

      Candidates: Kh2 (King oscillation in h1/g2/h2 box maintains stalemate cage; bishop e3 controls g1/f2, keeping White nearly stalemated.) | Kh1 (Retreat to h1 deepens stalemate trap; Black king on g4 approaching g3 risks g…

      • chess.js.legal_moves0ms
      • llm.candidates10421ms · $0.0039
      full reasoning
      Candidates: Kh2 (King oscillation in h1/g2/h2 box maintains stalemate cage; bishop e3 controls g1/f2, keeping White nearly stalemated.) | Kh1 (Retreat to h1 deepens stalemate trap; Black king on g4 approaching g3 risks gifting stalemate if no pawn moves remain.) | a3 (Burns a tempo with a pawn move extending survival; preserves king oscillation resource while delaying Black's mating net.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect196 tok · 8402ms · claude-sonnet-4-6 · $0.0029

      Final pick: Kh2 — King oscillation in the h1/h2/g2 box maintains the stalemate cage. Bishop e3 controls g1/f2, so Kh2 keeps maximum stalemate threat without burning irreversible pawn tempos.. Rejected: g2h1, a2a3.

      • llm.reflect8402ms · $0.0029
    • 9. Commit0 tok · 0ms

      Commit Kh2 (g2h2).

  70. 70...Bf4+Haiku21.184 tok · $0.1058 · 184888ms
    • 1. Observe0 tok · 0ms

      Halbzug 70, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 35. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 11ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search11ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3396 tok · 34755ms · claude-haiku-4-5 · $0.0169

      Phase: endgame. Force White king from h2 with forcing checks (Rh1+ critical), coordinate rook and bishop to deliver sequential mating threats, contain White's queenside pawns with rook placement. Mate within three moves.…

      • llm.plan34755ms · $0.0169
      full reasoning
      Phase: endgame. Force White king from h2 with forcing checks (Rh1+ critical), coordinate rook and bishop to deliver sequential mating threats, contain White's queenside pawns with rook placement. Mate within three moves. Deliver mate via rook-bishop mating net once king flees corner, or promote Black's c-file pawn after king is fatally separated from defending pawns. Critical: White king cornered with only three escape squares (g2, g3, h3); limited shelter; Black rook-bishop coordination creates unstoppable mating pattern; White has zero defensive resources; Black king (g4) controls f3, g3, h3—exit routes blocked; White pawns on a2-c2 are dead weight.
    • 6. Candidates8498 tok · 72799ms · claude-haiku-4-5 · $0.0425

      Candidates: Bf4+ (Forcing check forces king movement, coordinates rook-bishop for mating attack. After Kg1 or Kh1, Black delivers mate. Simplest tactical path to victory.) | Bg1+ (Aggressive check along long diagonal for…

      • chess.js.legal_moves0ms
      • llm.candidates72798ms · $0.0425
      full reasoning
      Candidates: Bf4+ (Forcing check forces king movement, coordinates rook-bishop for mating attack. After Kg1 or Kh1, Black delivers mate. Simplest tactical path to victory.) | Bg1+ (Aggressive check along long diagonal forces Kg2 or Kh1. Rook and bishop then coordinate for unstoppable mating net against trapped White king.) | Bd4 (Centralizes bishop to support rook's mating patterns. Controls key squares preventing king escape routes. Threatens Rh1# with White unable to defend.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect9290 tok · 77300ms · claude-haiku-4-5 · $0.0464

      Final pick: Bf4+ — Bf4+ forces Kg1 most naturally (Kg2/Kh1 are less natural escapes). The bishop controls g3 and h2 simultaneously. After Kg1, Rh1+ initiates a rook-bishop mating net with the king fatally cornered.. Reje…

      • llm.reflect77300ms · $0.0464
      full reasoning
      Final pick: Bf4+ — Bf4+ forces Kg1 most naturally (Kg2/Kh1 are less natural escapes). The bishop controls g3 and h2 simultaneously. After Kg1, Rh1+ initiates a rook-bishop mating net with the king fatally cornered.. Rejected: e3g1, e3d4.
    • 9. Commit0 tok · 0ms

      Commit Bf4+ (e3f4).

  71. 71.Kh1Sonnet744 tok · $0.0111 · 29865ms
    • 1. Observe0 tok · 0ms

      Halbzug 71, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 3. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 7ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search7ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan288 tok · 11539ms · claude-sonnet-4-6 · $0.0043

      Phase: endgame. Survive by oscillating the White king in the h1/h2/g2 corner to maintain the stalemate cage. With only 3 legal moves and -11 material, the sole drawing resource is forcing stalemate. Black bishop f4 and k…

      • llm.plan11539ms · $0.0043
      full reasoning
      Phase: endgame. Survive by oscillating the White king in the h1/h2/g2 corner to maintain the stalemate cage. With only 3 legal moves and -11 material, the sole drawing resource is forcing stalemate. Black bishop f4 and king g4 nearly box White in already. Exploit the stalemate trap: keep White king locked in the h1-h2 box so any Black mating attempt risks gifting stalemate — the opposition heuristic confirms Black king on g4 with bishop f4 creates a near-stalemate net that White must preserve, not escape. Critical: Black king g4 + bishop f4 nearly stalemated White king on h2 already; Only 3 legal moves — any king move risks either walking into mate or escaping the stalemate cage; Opposition heuristic: Black king g4 has direct opposition pressure on h3/h2/g2 — White must not give Black a clean route to h2 without stalemate gift.
    • 6. Candidates248 tok · 9415ms · claude-sonnet-4-6 · $0.0037

      Candidates: Kh1 (Deepest corner square; preserves stalemate cage with bishop f4 and Black king g4 nearly boxing White in.) | Kg1 (Oscillates within stalemate box; opposition heuristic confirms Black king g4 pressure make…

      • chess.js.legal_moves0ms
      • llm.candidates9415ms · $0.0037
      full reasoning
      Candidates: Kh1 (Deepest corner square; preserves stalemate cage with bishop f4 and Black king g4 nearly boxing White in.) | Kg1 (Oscillates within stalemate box; opposition heuristic confirms Black king g4 pressure makes g1 a drawing refuge.) | Kg2 (Maintains king in h1-h2-g2 stalemate zone; risks gifting stalemate if Black advances carelessly.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect208 tok · 8891ms · claude-sonnet-4-6 · $0.0031

      Final pick: Kh1 — Deepest corner square maximizes stalemate cage pressure. With bishop f4 and Black king g4, h1 forces Black to find a precise mating sequence or gift stalemate — any Black misstep with bishop f4 on h2 at…

      • llm.reflect8891ms · $0.0031
      full reasoning
      Final pick: Kh1 — Deepest corner square maximizes stalemate cage pressure. With bishop f4 and Black king g4, h1 forces Black to find a precise mating sequence or gift stalemate — any Black misstep with bishop f4 on h2 attempt stalemates White immediately.. Rejected: h2g1, h2g2.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (h2h1).

  72. 72...h4Haiku15.874 tok · $0.0793 · 144952ms
    • 1. Observe0 tok · 0ms

      Halbzug 72, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 35. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan4181 tok · 37342ms · claude-haiku-4-5 · $0.0209

      Phase: endgame. Force Kg1 via Rh2+, then coordinate Rook (h1 or 1st rank) with Bishop (controlling e3, d2, g3) to deliver back-rank mate. Mate in 3 moves. Checkmate via rook-bishop coordination on back rank. White King h…

      • llm.plan37342ms · $0.0209
      full reasoning
      Phase: endgame. Force Kg1 via Rh2+, then coordinate Rook (h1 or 1st rank) with Bishop (controlling e3, d2, g3) to deliver back-rank mate. Mate in 3 moves. Checkmate via rook-bishop coordination on back rank. White King has no escape after Kg1. Critical: Rh2+ forces Kg1 (only legal move); Bishop f4 controls e3, d2, g3—all escape squares; Black King g4 controls h3, f3—king cut off; White has zero counterplay or defense.
    • 6. Candidates7026 tok · 63843ms · claude-haiku-4-5 · $0.0351

      Candidates: h4 (Clears h-file for Rh2+ forcing Kg1, unlocking the mating sequence described in the plan.) | Be3 (Bishop controls d2, g1, f2—escape squares critical for the back-rank mating net after Kg1.) | Rh7 (Improves…

      • chess.js.legal_moves0ms
      • llm.candidates63841ms · $0.0351
      full reasoning
      Candidates: h4 (Clears h-file for Rh2+ forcing Kg1, unlocking the mating sequence described in the plan.) | Be3 (Bishop controls d2, g1, f2—escape squares critical for the back-rank mating net after Kg1.) | Rh7 (Improves Rook position on h-file in preparation for h2+ and coordinates with Bishop on back rank.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4667 tok · 43737ms · claude-haiku-4-5 · $0.0233

      Final pick: h4 — Clears the h-file so Rh2+ becomes possible next move, forcing Kg1 and unlocking the back-rank mating net.. Rejected: f4e3, h8h7.

      • llm.reflect43737ms · $0.0233
    • 9. Commit0 tok · 0ms

      Commit h4 (h5h4).

  73. 73.Kg1Sonnet760 tok · $0.0113 · 30231ms
    • 1. Observe0 tok · 0ms

      Halbzug 73, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 8. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan320 tok · 12403ms · claude-sonnet-4-6 · $0.0048

      Phase: endgame. Oscillate king in h1/h2/g2 corner to preserve stalemate cage. Black king g4 + bishop f4 nearly box White in — any Black mating attempt risks stalemate gift. Exploit the opposition heuristic: White king st…

      • llm.plan12403ms · $0.0048
      full reasoning
      Phase: endgame. Oscillate king in h1/h2/g2 corner to preserve stalemate cage. Black king g4 + bishop f4 nearly box White in — any Black mating attempt risks stalemate gift. Exploit the opposition heuristic: White king stuck on h1/h2 with 8 legal moves but stalemate net tightens as Black advances pawns. Hold the stalemate fortress in the h1-h2-g2 triangle — the only drawing resource with -11 material deficit is forcing Black into an inadvertent stalemate. Critical: Black h4 pawn advancing to h3 would shrink White legal moves toward stalemate — this is White's only chance; Bishop f4 + king g4 already form a near-stalemate net; White must NOT escape to open squares; Opposition heuristic: Black king on g4 with White king on h2 is the key cage — preserve it, do not drift to g1 or f-file; 8 legal moves currently — too many for stalemate, so White must stay passive and let Black constrict further.
    • 6. Candidates237 tok · 9395ms · claude-sonnet-4-6 · $0.0035

      Candidates: Kg1 (King stays in h1-g1-g2 stalemate triangle; avoids drifting to open squares per opposition heuristic.) | Kg2 (Oscillates within stalemate fortress triangle; preserves cage as Black king g4 tightens the ne…

      • chess.js.legal_moves0ms
      • llm.candidates9395ms · $0.0035
      full reasoning
      Candidates: Kg1 (King stays in h1-g1-g2 stalemate triangle; avoids drifting to open squares per opposition heuristic.) | Kg2 (Oscillates within stalemate fortress triangle; preserves cage as Black king g4 tightens the net.) | a3 (Passive pawn move burns tempo without escaping stalemate fortress; keeps king passive per plan.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect203 tok · 8398ms · claude-sonnet-4-6 · $0.0030

      Final pick: Kg1 — Kg1 keeps White in the stalemate triangle (g1-h1-h2). Black king on g4 + bishop f4 already form the cage; h4 advancing to h3 will shrink legal moves toward stalemate. g1 is the tightest corner square.. …

      • llm.reflect8397ms · $0.0030
      full reasoning
      Final pick: Kg1 — Kg1 keeps White in the stalemate triangle (g1-h1-h2). Black king on g4 + bishop f4 already form the cage; h4 advancing to h3 will shrink legal moves toward stalemate. g1 is the tightest corner square.. Rejected: h1g2, a2a3.
    • 9. Commit0 tok · 0ms

      Commit Kg1 (h1g1).

  74. 74...Be3+Haiku25.480 tok · $0.1273 · 215135ms
    • 1. Observe0 tok · 0ms

      Halbzug 74, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 36. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 21ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search21ms
    • 3. Recall Opponent0 tok · 13ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search13ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan3868 tok · 39269ms · claude-haiku-4-5 · $0.0193

      Phase: endgame. Rook infiltrates to 1st rank via Rh1+ to force White King away, then coordinate with Bishop f4 (controlling d2, e3, g3) and King g4 (controlling h3, f3) to deliver back-rank mate. White King is mated with…

      • llm.plan39269ms · $0.0193
      full reasoning
      Phase: endgame. Rook infiltrates to 1st rank via Rh1+ to force White King away, then coordinate with Bishop f4 (controlling d2, e3, g3) and King g4 (controlling h3, f3) to deliver back-rank mate. White King is mated within 3-4 moves. Rook locks down the rank, Bishop seals escape squares, Black King completes the net. Unstoppable. Critical: Rh1+ is the forcing move that activates the mating attack; Bishop f4 must maintain control of d2/e3/g3 to prevent King flight; Black King g4 blocks h3/f3—net is airtight; White has no defense or counterplay with bare King.
    • 6. Candidates10997 tok · 87864ms · claude-haiku-4-5 · $0.0549

      Candidates: Be3+ (Checks King, forces away from g1, controls d2 escape square for mating net.) | Bh2+ (Checks King, controls h2-g1 diagonal, supports h1 square for Rh1+ back-rank mate.) | Be5 (Centralizes Bishop, control…

      • chess.js.legal_moves0ms
      • llm.candidates87861ms · $0.0549
      full reasoning
      Candidates: Be3+ (Checks King, forces away from g1, controls d2 escape square for mating net.) | Bh2+ (Checks King, controls h2-g1 diagonal, supports h1 square for Rh1+ back-rank mate.) | Be5 (Centralizes Bishop, controls g3 escape square, prepares mating attack flexibility.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect10615 tok · 87948ms · claude-haiku-4-5 · $0.0530

      Final pick: Be3+ — Checks King, controls d2/f2 escapes, sets up Rh1+ back-rank mate. Tightest control of White King's options.. Rejected: f4h2, f4e5.

      • llm.reflect87948ms · $0.0530
    • 9. Commit0 tok · 0ms

      Commit Be3+ (f4e3).

  75. 75.Kh1Sonnet772 tok · $0.0115 · 30737ms
    • 1. Observe0 tok · 0ms

      Halbzug 75, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 4. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan307 tok · 11439ms · claude-sonnet-4-6 · $0.0046

      Phase: endgame. Oscillate king within the g1/h1/h2 triangle to preserve the stalemate fortress. Black h4-pawn advancing to h3 shrinks White's legal moves — this tightens the stalemate net, which is White's only drawing r…

      • llm.plan11439ms · $0.0046
      full reasoning
      Phase: endgame. Oscillate king within the g1/h1/h2 triangle to preserve the stalemate fortress. Black h4-pawn advancing to h3 shrinks White's legal moves — this tightens the stalemate net, which is White's only drawing resource with -11 material deficit. Force Black into accidental stalemate by keeping White king trapped in the corner triangle while Black's bishop+king+pawns box tighter — the opposition heuristic confirms holding the corner is the only path to half a point. Critical: Only 4 legal moves remain — any move leaving g1/h1/h2 triangle risks losing stalemate fortress; Black bishop e3 + king g4 nearly complete the mating net — stalemate is the sole defensive resource; Black h4-pawn advance to h3 reduces White legal moves further, paradoxically helping stalemate goal; do not block it; White pawns a2/b2/c2 are irrelevant — king safety (stalemate cage) is the only factor.
    • 6. Candidates249 tok · 9883ms · claude-sonnet-4-6 · $0.0037

      Candidates: Kh1 (Deep corner — opposition heuristic confirms h1 tightens stalemate cage; Black bishop e3 cannot cover h1 escape.) | Kh2 (Stays within g1/h1/h2 triangle; stalemate fortress heuristic: oscillate corner tria…

      • chess.js.legal_moves0ms
      • llm.candidates9883ms · $0.0037
      full reasoning
      Candidates: Kh1 (Deep corner — opposition heuristic confirms h1 tightens stalemate cage; Black bishop e3 cannot cover h1 escape.) | Kh2 (Stays within g1/h1/h2 triangle; stalemate fortress heuristic: oscillate corner triangle only.) | Kg2 (Remains near triangle but risks Kf1 exit — only if h1/h2 are covered by Black bishop.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect216 tok · 9374ms · claude-sonnet-4-6 · $0.0032

      Final pick: Kh1 — Deep corner h1 tightens stalemate cage maximally. Opposition heuristic confirms h1 is the tightest corner — bishop e3 cannot cover h1, and Black's h4-h3 advance will further reduce White's legal moves, …

      • llm.reflect9374ms · $0.0032
      full reasoning
      Final pick: Kh1 — Deep corner h1 tightens stalemate cage maximally. Opposition heuristic confirms h1 is the tightest corner — bishop e3 cannot cover h1, and Black's h4-h3 advance will further reduce White's legal moves, paradoxically strengthening the stalemate fortress.. Rejected: g1h2, g1g2.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (g1h1).

  76. 76...h3Haiku11.842 tok · $0.0591 · 117457ms
    • 1. Observe0 tok · 0ms

      Halbzug 76, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 38. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan2144 tok · 23944ms · claude-haiku-4-5 · $0.0107

      Phase: endgame. Execute Rh1+ to force White King away from h1, then coordinate Rook on 1st rank + Bishop repositioned to f4 + Black King advance to deliver unstoppable back-rank mate within 3 moves. Checkmate White King …

      • llm.plan23944ms · $0.0107
      full reasoning
      Phase: endgame. Execute Rh1+ to force White King away from h1, then coordinate Rook on 1st rank + Bishop repositioned to f4 + Black King advance to deliver unstoppable back-rank mate within 3 moves. Checkmate White King via forced sequence: Rh1+ drives King away, Bishop-to-f4 seals escape squares (h2, g3, g2), Black King advances to f2/f1 to complete mating net. Critical: Rh1+ is the forcing tactical blow—activates the mating attack immediately and gives White no choice; Bishop must occupy f4 or d2 to control h2, g3, g2 escape squares (currently e3, must move); White King is bare with zero defensive resources—cannot counter, stall, or escape the mating sequence; Black King on g4 controls h3/f3; must advance toward f2/f1 after Rh1+ to complete the net.
    • 6. Candidates3457 tok · 36038ms · claude-haiku-4-5 · $0.0172

      Candidates: h3 (Clears h-file for Rh1+; unstoppable back-rank mate threat forces White collapse) | Bf4 (Seizes h2, g2, g3 escape squares; completes mating net with rook and king) | Kg3 (King advance toward f1; threatens …

      • chess.js.legal_moves0ms
      • llm.candidates36037ms · $0.0172
      full reasoning
      Candidates: h3 (Clears h-file for Rh1+; unstoppable back-rank mate threat forces White collapse) | Bf4 (Seizes h2, g2, g3 escape squares; completes mating net with rook and king) | Kg3 (King advance toward f1; threatens h2# and supports final mating sequence)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6241 tok · 57436ms · claude-haiku-4-5 · $0.0312

      Final pick: h3 — h3 is the forcing blow that clears the h-file and threatens Rh1+ with unavoidable back-rank mate. After h3, if White plays Kg1, then Rh1# is mate; if Kg2, then Bf4 seals the mating net. Most forcing.. Re…

      • llm.reflect57436ms · $0.0312
      full reasoning
      Final pick: h3 — h3 is the forcing blow that clears the h-file and threatens Rh1+ with unavoidable back-rank mate. After h3, if White plays Kg1, then Rh1# is mate; if Kg2, then Bf4 seals the mating net. Most forcing.. Rejected: e3f4, g4g3.
    • 9. Commit0 tok · 0ms

      Commit h3 (h4h3).

  77. 77.Kh2Sonnet724 tok · $0.0108 · 28975ms
    • 1. Observe0 tok · 0ms

      Halbzug 77, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 7. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 17ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search17ms
    • 3. Recall Opponent0 tok · 10ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search10ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan282 tok · 10913ms · claude-sonnet-4-6 · $0.0042

      Phase: endgame. Maintain stalemate fortress by oscillating king within the g1/h1/h2 corner triangle. With only 7 legal moves and -11 material, stalemate is the only drawing resource. Black's h3-pawn and bishop e3 tighten…

      • llm.plan10913ms · $0.0042
      full reasoning
      Phase: endgame. Maintain stalemate fortress by oscillating king within the g1/h1/h2 corner triangle. With only 7 legal moves and -11 material, stalemate is the only drawing resource. Black's h3-pawn and bishop e3 tighten the net — this is what we want. Force accidental stalemate by keeping the White king trapped in the h1/g1/h2 triangle while Black's pieces box closer — the opposition heuristic confirms corner confinement is the only path to half a point. Critical: Black h3-pawn reduces White legal moves — tightening stalemate net (good for us); Bishop e3 controls key escape squares; Any king move outside g1/h1/h2 triangle breaks the stalemate fortress; Opposition heuristic: staying cornered forces Black to navigate around stalemate trap; Philidor/Lucena rook heuristics not applicable here — we have no rook, stalemate geometry governs.
    • 6. Candidates245 tok · 8635ms · claude-sonnet-4-6 · $0.0036

      Candidates: Kh2 (King oscillates within stalemate triangle g1/h1/h2; corner confinement heuristic — stay trapped to force stalemate.) | a3 (Pawn move delays Black's winning plan; opposition heuristic confirms reducing le…

      • chess.js.legal_moves0ms
      • llm.candidates8634ms · $0.0036
      full reasoning
      Candidates: Kh2 (King oscillates within stalemate triangle g1/h1/h2; corner confinement heuristic — stay trapped to force stalemate.) | a3 (Pawn move delays Black's winning plan; opposition heuristic confirms reducing legal moves tightens stalemate net.) | b3 (Alternative pawn tempo; keeps king cornered in h1/h2 triangle while Black must navigate stalemate geometry.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect197 tok · 9390ms · claude-sonnet-4-6 · $0.0029

      Final pick: Kh2 — Corner confinement heuristic: king must oscillate within g1/h1/h2 triangle. Pawn moves consume our only tempo resources — saving them extends the stalemate fortress longer by preserving future oscillati…

      • llm.reflect9390ms · $0.0029
      full reasoning
      Final pick: Kh2 — Corner confinement heuristic: king must oscillate within g1/h1/h2 triangle. Pawn moves consume our only tempo resources — saving them extends the stalemate fortress longer by preserving future oscillation options.. Rejected: a2a3, b2b3.
    • 9. Commit0 tok · 0ms

      Commit Kh2 (h1h2).

  78. 78...Bf4+Haiku13.734 tok · $0.0686 · 124900ms
    • 1. Observe0 tok · 0ms

      Halbzug 78, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 37. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 8ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search8ms
    • 3. Recall Opponent0 tok · 7ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search7ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan1813 tok · 21316ms · claude-haiku-4-5 · $0.0090

      Phase: endgame. Execute Rh1+ to seize 1st rank and force White King to g3. Follow with Bf4+ to control escape squares (h2, g2, e3). Black King advances to seal mating cage. Forced mate in 2-3 moves. Deliver checkmate via…

      • llm.plan21316ms · $0.0090
      full reasoning
      Phase: endgame. Execute Rh1+ to seize 1st rank and force White King to g3. Follow with Bf4+ to control escape squares (h2, g2, e3). Black King advances to seal mating cage. Forced mate in 2-3 moves. Deliver checkmate via forced back-rank mating sequence. White King is cornered (h2)—no flight squares remain after Rh1+ and Bf4+. Mate is inevitable within 3 moves. Critical: Rh1+ is the only forcing tactical blow that activates mating attack immediately; Bishop must occupy f4 or d2 to seal h2/g3/g2 escape squares; White has zero defensive resources—only pawns, no pieces to block or counterattack.
    • 6. Candidates6042 tok · 53273ms · claude-haiku-4-5 · $0.0302

      Candidates: Bf4+ (Forcing check, controls g3/e3, directly advances mating plan outlined in strategic notes.) | Bg1+ (Forcing check from long diagonal, restricts escape routes, alternative kingside net tightening.) | Bd4 …

      • chess.js.legal_moves0ms
      • llm.candidates53270ms · $0.0302
      full reasoning
      Candidates: Bf4+ (Forcing check, controls g3/e3, directly advances mating plan outlined in strategic notes.) | Bg1+ (Forcing check from long diagonal, restricts escape routes, alternative kingside net tightening.) | Bd4 (Centralizes bishop on dominant diagonal, flexible support for follow-up mating combinations and checks.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect5879 tok · 50285ms · claude-haiku-4-5 · $0.0294

      Final pick: Bf4+ — Bf4+ is the only move that forces immediate check while controlling g3 and h2 escape squares. After Kh1, Kg3 seals the mating cage with h2 promotion imminent. Kg2 allows h2+ driving the King further. M…

      • llm.reflect50285ms · $0.0294
      full reasoning
      Final pick: Bf4+ — Bf4+ is the only move that forces immediate check while controlling g3 and h2 escape squares. After Kh1, Kg3 seals the mating cage with h2 promotion imminent. Kg2 allows h2+ driving the King further. Maximally forcing.. Rejected: e3g1, e3d4.
    • 9. Commit0 tok · 0ms

      Commit Bf4+ (e3f4).

  79. 79.Kh1Sonnet754 tok · $0.0112 · 31786ms
    • 1. Observe0 tok · 1ms

      Halbzug 79, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 2. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 21ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search21ms
    • 3. Recall Opponent0 tok · 8ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search8ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan343 tok · 15372ms · claude-sonnet-4-6 · $0.0051

      Phase: endgame. With only 2 legal moves and -11 material, the sole objective is provoking stalemate. Keep the White king oscillating within the h1/h2 corner, forcing Black to tighten the net until accidental stalemate oc…

      • llm.plan15372ms · $0.0051
      full reasoning
      Phase: endgame. With only 2 legal moves and -11 material, the sole objective is provoking stalemate. Keep the White king oscillating within the h1/h2 corner, forcing Black to tighten the net until accidental stalemate occurs. Any king move that reduces legal moves further is desirable. Survive by manufacturing stalemate — the corner confinement heuristic (opposition principle applied to king-trapping) confirms h1/h2 oscillation as the only half-point resource against a materially overwhelming opponent. Critical: Only 2 legal moves remain — stalemate net is nearly complete (desirable); Black h3-pawn + Bf4 severely restrict White king escape squares — use this, not fight it; Opposition heuristic: White king must stay maximally confined to h1/h2 to deny Black a clean zugzwang-free win; Philidor/Lucena rook heuristics irrelevant here — no rooks; stalemate geometry is the only applicable endgame principle; Risk: any move that gives Black a tempo to reposition Bf4 off the stalemate diagonal could allow a clean mating net instead of stalemate.
    • 6. Candidates247 tok · 8994ms · claude-sonnet-4-6 · $0.0037

      Candidates: Kh1 (Corner confinement heuristic: h1 maximally restricts king, forcing stalemate geometry with Bf4 on diagonal.) | Kg1 (Opposition principle: g1 oscillation keeps king confined, maintaining stalemate net wit…

      • chess.js.legal_moves0ms
      • llm.candidates8994ms · $0.0037
      full reasoning
      Candidates: Kh1 (Corner confinement heuristic: h1 maximally restricts king, forcing stalemate geometry with Bf4 on diagonal.) | Kg1 (Opposition principle: g1 oscillation keeps king confined, maintaining stalemate net with h3-pawn restriction.) | Kh1 (Only 2 legal moves; h1/g1 oscillation is sole half-point resource — repeat to manufacture stalemate.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect164 tok · 7380ms · claude-sonnet-4-6 · $0.0024

      Final pick: Kh1 — Corner confinement heuristic: Kh1 maximally restricts escape squares. With Bf4 on the stalemate diagonal and h3-pawn sealing the net, h1 forces stalemate geometry faster than g1 oscillation.. Rejected: …

      • llm.reflect7380ms · $0.0024
      full reasoning
      Final pick: Kh1 — Corner confinement heuristic: Kh1 maximally restricts escape squares. With Bf4 on the stalemate diagonal and h3-pawn sealing the net, h1 forces stalemate geometry faster than g1 oscillation.. Rejected: h2g1.
    • 9. Commit0 tok · 0ms

      Commit Kh1 (h2h1).

  80. 80...h2Haiku21.556 tok · $0.1077 · 191503ms
    • 1. Observe0 tok · 0ms

      Halbzug 80, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 37. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 14ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search14ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan6933 tok · 61832ms · claude-haiku-4-5 · $0.0346

      Phase: endgame. Advance h-file pawn toward promotion with Rook and Bishop support. White King trapped with no defensive pieces. Promotion threat forces imminent checkmate. Push advanced h-pawn to queening square via Rook…

      • llm.plan61832ms · $0.0346
      full reasoning
      Phase: endgame. Advance h-file pawn toward promotion with Rook and Bishop support. White King trapped with no defensive pieces. Promotion threat forces imminent checkmate. Push advanced h-pawn to queening square via Rook-Bishop coordination. White King locked down—no escape routes, zero pieces to defend. Mate follows promotion. Critical: h-file pawn threatens imminent queening (one move away); White King lacks flight squares and all defensive resources; Rook and Bishop ensure pawn promotion is unstoppable.
    • 6. Candidates7794 tok · 66282ms · claude-haiku-4-5 · $0.0389

      Candidates: h2 (Direct pawn advance toward promotion. Threatens h1=Q next move, forcing White King away with limited options.) | Rh7 (Rook to h7 supports pawn, controls h-file, restricts White King escape routes, prepare…

      • chess.js.legal_moves0ms
      • llm.candidates66281ms · $0.0389
      full reasoning
      Candidates: h2 (Direct pawn advance toward promotion. Threatens h1=Q next move, forcing White King away with limited options.) | Rh7 (Rook to h7 supports pawn, controls h-file, restricts White King escape routes, prepares promotion sequence.) | Be5 (Bishop to e5 controls escape squares g3, h2. Limits White King mobility, ensures pawn promotion unstoppable.)
    • 7. Verify0 tok · 1ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect6829 tok · 63353ms · claude-haiku-4-5 · $0.0341

      Final pick: h2 — Direct pawn advance to h2 forces imminent h1=Q next move. White's only tries: Kg1 allows h1=Q+ with check; Kxh2 allows Rh1 driving King away. Most forcing, immediate promotion threat.. Rejected: h8h7, f4…

      • llm.reflect63353ms · $0.0341
      full reasoning
      Final pick: h2 — Direct pawn advance to h2 forces imminent h1=Q next move. White's only tries: Kg1 allows h1=Q+ with check; Kxh2 allows Rh1 driving King away. Most forcing, immediate promotion threat.. Rejected: h8h7, f4e5.
    • 9. Commit0 tok · 0ms

      Commit h2 (h3h2).

  81. 81.Kg2Sonnet618 tok · $0.0092 · 27585ms
    • 1. Observe0 tok · 0ms

      Halbzug 81, Weiss am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 7. Criticality: 0.00. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 5ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search5ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan220 tok · 10056ms · claude-sonnet-4-6 · $0.0033

      Phase: endgame. Oscillate king between h1 and h2 to maintain stalemate trap. With only 7 legal moves and -11 material, any move that reduces Black's winning options or provokes accidental stalemate is the sole resource. …

      • llm.plan10056ms · $0.0033
      full reasoning
      Phase: endgame. Oscillate king between h1 and h2 to maintain stalemate trap. With only 7 legal moves and -11 material, any move that reduces Black's winning options or provokes accidental stalemate is the sole resource. Stay in the h1/h2 corner. Manufacture stalemate by keeping the White king trapped in the h1/h2 corner — the opposition principle confirms corner confinement as the only drawing resource against overwhelming material deficit. Critical: Black h2-pawn promotes next move if unchallenged; White king must stay in h1/h2 to minimize legal moves and invite stalemate; Philidor/opposition memory hits confirm king passivity in corner is correct — no active defense exists.
    • 6. Candidates225 tok · 8587ms · claude-sonnet-4-6 · $0.0033

      Candidates: Kg2 (King actively contests h2-pawn promotion square; only move that directly challenges Black's winning plan.) | a3 (Corner confinement principle: pawn move preserves stalemate trap by reducing White's legal…

      • chess.js.legal_moves0ms
      • llm.candidates8586ms · $0.0033
      full reasoning
      Candidates: Kg2 (King actively contests h2-pawn promotion square; only move that directly challenges Black's winning plan.) | a3 (Corner confinement principle: pawn move preserves stalemate trap by reducing White's legal moves.) | b3 (Minimizes legal moves per opposition/stalemate memory heuristic; keeps king passively in corner.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect173 tok · 8918ms · claude-sonnet-4-6 · $0.0026

      Final pick: Kg2 — King must contest h2 promotion square directly — h2 promotes to queen next move if unchallenged. Corner confinement heuristic is irrelevant when opponent has unstoppable promotion in one.. Rejected: a2a…

      • llm.reflect8918ms · $0.0026
      full reasoning
      Final pick: Kg2 — King must contest h2 promotion square directly — h2 promotes to queen next move if unchallenged. Corner confinement heuristic is irrelevant when opponent has unstoppable promotion in one.. Rejected: a2a3, b2b3.
    • 9. Commit0 tok · 0ms

      Commit Kg2 (h1g2).

  82. 82...h1=Q+Haiku13.828 tok · $0.0690 · 131273ms
    • 1. Observe0 tok · 0ms

      Halbzug 82, Schwarz am Zug. Phase: Endspiel. Schwarz +11 Punkte. Legale Zuege: 38. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 10ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search10ms
    • 3. Recall Opponent0 tok · 13ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search13ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan1845 tok · 22947ms · claude-haiku-4-5 · $0.0092

      Phase: endgame. Remove White King from h1 control via Rh2+ check, then h1=Q on next move. Promotion forces immediate checkmate. No White defensive pieces remain. h-pawn promotion is inevitable once Kg2 abandons h1 defens…

      • llm.plan22947ms · $0.0092
      full reasoning
      Phase: endgame. Remove White King from h1 control via Rh2+ check, then h1=Q on next move. Promotion forces immediate checkmate. No White defensive pieces remain. h-pawn promotion is inevitable once Kg2 abandons h1 defense. Rook check dislodges the King; queening follows immediately with unstoppable mate. Critical: Kg2 currently blocks h1, the only barrier to promotion; Rh2+ forces King away and opens queening square; Zero White resources to defend—promotion = automatic checkmate sequence.
    • 6. Candidates10675 tok · 89880ms · claude-haiku-4-5 · $0.0533

      Candidates: h1=Q+ (Promotes to Queen with check, forcing Kg1/Kf1/Kf2/Kf3/Kh2, sealing victory immediately.) | h1=B+ (Promotes to Bishop with check, maintains Rook protection on h1, forces King away.) | Be5 (Centralizes B…

      • chess.js.legal_moves0ms
      • llm.candidates89875ms · $0.0533
      full reasoning
      Candidates: h1=Q+ (Promotes to Queen with check, forcing Kg1/Kf1/Kf2/Kf3/Kh2, sealing victory immediately.) | h1=B+ (Promotes to Bishop with check, maintains Rook protection on h1, forces King away.) | Be5 (Centralizes Bishop to strong diagonal, controls d4, c3, b2 and f6, g7 squares.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect1308 tok · 18405ms · claude-haiku-4-5 · $0.0065

      Final pick: h1=Q+ — Queen achieves mating net fastest. Kg2 in check, forced to move; h1 opens for promotion next turn if needed. Rook+Queen+Bishop vs pawns = unstoppable.. Rejected: h2h1b, f4e5.

      • llm.reflect18405ms · $0.0065
    • 9. Commit0 tok · 0ms

      Commit h1=Q+ (h2h1q).

  83. 83.Kf2Sonnet380 tok · $0.0056 · 18042ms
    • 1. Observe0 tok · 0ms

      Halbzug 83, Weiss am Zug. Phase: Endspiel. Schwarz +19 Punkte. Legale Zuege: 1. Schach! Criticality: 0.45. AUFGABE empfohlen (Material-Floor).

      • material-counter0ms
    • 2. Recall Position0 tok · 15ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search15ms
    • 3. Recall Opponent0 tok · 6ms

      No pattern found for chess-haiku-tm (tag=chess-haiku-tm) — mandatory run documented.

      • nex_entity_search6ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan280 tok · 11042ms · claude-sonnet-4-6 · $0.0042

      Phase: endgame. With only 1 legal move available, execute it. Position is completely lost (-19 material, Black has queen+bishop vs bare king). The sole resource is stalemate — keep the White king maximally confined. The …

      • llm.plan11042ms · $0.0042
      full reasoning
      Phase: endgame. With only 1 legal move available, execute it. Position is completely lost (-19 material, Black has queen+bishop vs bare king). The sole resource is stalemate — keep the White king maximally confined. The opposition heuristic confirms corner confinement as the only drawing concept; Philidor/Lucena rook heuristics are irrelevant here (no rook), but the opposition principle applies: stay cornered, minimize legal moves, invite Black to accidentally stalemate. Manufacture stalemate by keeping the White king trapped in the g2/h1/h2 corner — with only 1 legal move, there is no choice; execute it and pray Black overpresses. Critical: only 1 legal move exists — no strategic choice available; Black queen on h1 + bishop on f4 + king on g4 means White is near zugzwang; stalemate is the only drawing resource; any Black inaccuracy delivering stalemate wins half a point.
    • 6. Candidates100 tok · 6965ms · claude-sonnet-4-6 · $0.0015

      Candidates: Kf2 (Only legal move. King safety heuristic: stay active, avoid corner zugzwang, seek stalemate via Black overpressing.)

      • chess.js.legal_moves0ms
      • llm.candidates6965ms · $0.0015
    • 7. Verify0 tok · 0ms

      Alle 1 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect0 tok · 0ms

      Final pick: Kf2 — Only legal move. King safety heuristic: stay active, avoid corner zugzwang, seek stalemate via Black overpressing.. Rejected: —.

    • 9. Commit0 tok · 0ms

      Commit Kf2 (g2f2).

  84. 84...Rh2#Haiku14.571 tok · $0.0727 · 123487ms
    • 1. Observe0 tok · 0ms

      Halbzug 84, Schwarz am Zug. Phase: Endspiel. Schwarz +19 Punkte. Legale Zuege: 55. Criticality: 0.10.

      • material-counter0ms
    • 2. Recall Position0 tok · 11ms

      recall: 5 similar position(s) found (limit=5).

      • nex_search11ms
    • 3. Recall Opponent0 tok · 9ms

      No pattern found for chess-sonnet-tm (tag=chess-sonnet-tm) — mandatory run documented.

      • nex_entity_search9ms
    • 4. Research0 tok · 0ms · skipped

      middlegame/endgame — research not relevant when both tools off.

    • 5. Plan4709 tok · 41279ms · claude-haiku-4-5 · $0.0235

      Phase: endgame. Displace White's exposed King via Rh2+ check, then coordinate Queen and Rook into a mating net. King will be flushed from f2 with no escape—all squares controlled by Black's attacking pieces. Forced check…

      • llm.plan41279ms · $0.0235
      full reasoning
      Phase: endgame. Displace White's exposed King via Rh2+ check, then coordinate Queen and Rook into a mating net. King will be flushed from f2 with no escape—all squares controlled by Black's attacking pieces. Forced checkmate in 5–8 moves. Overwhelming material advantage means pure tactical execution only; no strategic regrouping needed. Critical: White King on f2 is the sole active piece with zero defending resources or escape squares; Black Rook on h8 must deliver forcing checks (Rh2+) to rupture King's position; Black Queen on h1 pivots to f1 or g1 for immediate mate threats; all refuge squares blocked; White has no counter-play, no pieces to interpose, no defensive moves—only the King remains.
    • 6. Candidates5635 tok · 48251ms · claude-haiku-4-5 · $0.0281

      Candidates: Rh2# (Delivers checkmate in one move. White King has no escape squares.) | Bg3+ (Forcing check supporting mating attack. Bishop controls key escape squares.) | Be3+ (Forcing check. Bishop controls e2 and e3, …

      • chess.js.legal_moves0ms
      • llm.candidates48246ms · $0.0281
      full reasoning
      Candidates: Rh2# (Delivers checkmate in one move. White King has no escape squares.) | Bg3+ (Forcing check supporting mating attack. Bishop controls key escape squares.) | Be3+ (Forcing check. Bishop controls e2 and e3, restricting King's escape.)
    • 7. Verify0 tok · 0ms

      Alle 3 Kandidaten legal. cloud_eval disabled (default).

      • chess.js.legal_recheck0ms
    • 8. Reflect4227 tok · 33918ms · claude-haiku-4-5 · $0.0211

      Final pick: Rh2# — Rh2 delivers immediate checkmate. All escape squares sealed: e1/e2/g2/h3 by Rook; e1/f1/f3/g1 by Queen; e3/g3 by Bishop. No refuge.. Rejected: f4g3, f4e3.

      • llm.reflect33917ms · $0.0211
    • 9. Commit0 tok · 0ms

      Commit Rh2# (h8h2).

PGN

PGN anzeigen
[Event "Tournament Pairing 1"]
[Site "?"]
[Date "2026-05-31"]
[Round "?"]
[White "chess-sonnet-tm"]
[Black "chess-haiku-tm"]
[Result "*"]

1. e4 d5 2. d4 Nf6 3. Nf3 e5 4. Nc3 Bg4 5. Be2 Nxe4 6. O-O Nc6 7. Nxe4 exd4 8. h3 dxe4 9. Nxd4 Nxd4 10. Qxd4 Bxe2 11. Qxd8+ Rxd8 12. Re1 Kd7 13. Rxe2 e3 14. Rxe3 Re8 15. Re7+ Kxe7 16. Bg5+ Ke6 17. Re1+ Kd5 18. Re5+ Kxe5 19. Bf4+ Kxf4 20. g3+ Ke4 21. f3+ Kxf3 22. Kh1 Re1+ 23. Kh2 Re2+ 24. Kh1 Re1+ 25. Kh2 Re2+ 26. Kh1 Rh2+ 27. Kxh2 h5 28. Kg1 Kxg3 29. Kh1 Kxh3 30. Kg1 Bc5+ 31. Kh1 Kg4 32. Kg2 Bd4 33. Kh1 Bf2 34. Kg2 Be3 35. Kh2 Bf4+ 36. Kh1 h4 37. Kg1 Be3+ 38. Kh1 h3 39. Kh2 Bf4+ 40. Kh1 h2 41. Kg2 h1=Q+ 42. Kf2 Rh2# *