The Opera Game · 1858
45% of club players play Qb7 here — and it misses a forced mate in 1
4kb1r/p2n1ppp/4q3/4p1B1/4P3/1Q6/PPP2PPP/2KR4 w k - 0 1645% of players rated around 1500 play Qb7
in this position. It is the natural move, and it is not the best one.
| Move | Played by | Evaluation |
|---|---|---|
Qb7 the reflex | 45% of 1500-rated humans | +346 centipawns |
Qb8+ the move | 21% | mate in 1 and it is mate |
The move is Qb8+, which forces mate in 1. The reflex does not — it leaves an ordinary position. — forced mate.
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 45% 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.