Reasoning eval · Puzzle WvhFG

1 of 3 models found the move, and said 7 false things along the way

Green is the solution, red is what the model played when it differed. Each claim below was pulled out of the prose beside it and checked against this exact position.

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SolutionPlayedWhite to move
Rating
1239(1200 band)
Solution
f5e7 c6e7 d3h7
Motifs
clearancekingsideAttackmatemateIn2middlegamesacrificeshort
FEN
r4rk1/2pb1pp1/2n2q1p/p3pN2/1p1P3P/3Q4/PPB2PP1/R3R1K1 w - - 0 21
MissedPlayed f5h6(lost a forced mate)Claims true 33%4297 out · $0.0437 · 53.0s

Stated plan

Sacrifice the knight with a check to open the diagonal for a queen mate on h7.

Reasoning

The knight on f5 and queen on d3 form a battery along the a2-g8 diagonal, currently blocked by the knight itself. Playing Nh6+ forces gxh6 (since Kh8/Kh7 allow strong follow-ups too, but the pawn capture is natural), which clears the f5-g6-h7 diagonal completely for the queen. Then Qh7# is checkmate: the king on g8 has no escape (f8 blocked by its own rook, f7 blocked by pawn, g7 and g8 covered by the queen, h8 covered along the file), and Qh7 is not defended against or capturable. This is a forced mating combination.

Claims extracted from it

1 true · 2 false · 3 unverifiable

Hover a claim to light up the squares it is about.

  • Unverifiable

    The knight on f5 and queen on d3 form a battery along the a2-g8 diagonal

    unverifiable

  • False

    Playing Nh6+ forces gxh6

    lineprefix=playedmoves=Nh6+assertion=type:forced_reply

  • True

    After Nh6+ gxh6, Qh7# is checkmate

    lineprefix=playedmoves=Nh6+ gxh6 Qh7assertion=type:is_mate

  • Unverifiable

    After Nh6+ Kh8, strong follow-ups are available

    lineprefix=playedmoves=Nh6+ Kh8assertion=type:unverifiable

  • False

    After Nh6+ Kh7, strong follow-ups are available

    lineprefix=playedmoves=Nh6+ Kh7assertion=type:unverifiable

  • Unverifiable

    This is a forced mating combination

    unverifiable