The Machine That Beat the Champion · 1997
65% of club players play Qxf5 here — and it throws away 3.2 pawns
r1k4r/p2nb1p1/2b4p/1p1n1p2/3P4/3Q1NB1/1PP2PPP/R5K1 w - - 0 1965% of players rated around 1500 play Qxf5
in this position. It is the natural move, and it is not the best one.
| Move | Played by | Evaluation |
|---|---|---|
Qxf5 the reflex | 65% of 1500-rated humans | +117 centipawns |
c4 the move | 8% | +441 centipawns |
The difference is 3.2 pawns — a pin (the bishop on c6 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 65% 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.