The Mexican Immortal · 1920
42% of club players play Qxb7 here — and it throws away 4.1 pawns
2r1r1k1/1pQ2ppp/3p1b2/p2P4/q7/5N2/1P2RPPP/4R1K1 w - - 0 2242% of players rated around 1500 play Qxb7
in this position. It is the natural move, and it is not the best one.
| Move | Played by | Evaluation |
|---|---|---|
Qxb7 the reflex | 42% of 1500-rated humans | -9 centipawns |
Re4 the move | under 1% | +401 centipawns |
The difference is 4.1 pawns — a pin (the rook on e8 is pinned).
How this was checked
The evaluations are Stockfish. The human percentages are
Maia, a neural network trained on millions of human games and
conditioned on rating — so 42% of players around 1500
is a measurement of what people
actually do, not an estimate of what they might. Any tactical motif named above is verified against
the board geometry rather than described.
Paste a chess.com game you played and ChessCast makes a 10-20 minute coaching podcast about it — two hosts on the audio, and a board that moves in lock-step so you can watch the moment it turned. Every claim is checked against Stockfish before it is spoken.