Yesterday's position is from a game Zhang v Edwards, Oxford University v Witney, February 2005, Oxford and District League Division One.
White won with 10.Nxd6 mate. This, despite the fact that the pawn he was taking on d6 was his own.
The game had begun 1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.Bg5 c6 5.e5 Nd5 6.Ne4 Qc7 7.c4 Nb6 8.exd6 Qd8 producing the following position:
Our narration is from issue #29 of Cowley Chess Club's review, The Chequered Board.
Marco [i.e. Zhang, player of the White pieces - ejh] had recently played a quick game where his opponent walked into a smothered mate and so, spotting a similar pattern, he played 9.Qe2! threatening 10.Nf6#. Black defended this with 9...N8d7 [reaching our initial diagram - ejh] but this blocks the flight square on d7 so 10.Nxd6!# - forgetting that, unusually, the pawn on d6 is a white one - a twenty-first century chessboard classic.The incident was a complete brainstorm: no subterfuge was intended and neither player realised what had happened until later. (White, for his part, thought when playing through the game that he must have missed some moves off his scoresheet before he realised what he'd done.)
The result stood.
The game is reproduced below. Sort of.
(Thanks to Sean Terry and Marco Zhang for their help.)
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