The diagrammed position was reached after 29 moves of an Indian Teams Championship game, with White to move. The player with the White pieces was a Grandmaster. The player with the Black pieces was young and untitled.

White was in the dire position of facing simultaneous checkmate threats on g2 and f1 from Black’s Queen on d5 and Rook on f6, respectively, supported by Black’s Bishop on h3. Could White escape checkmate? White’s Rook on c5 was threatening to capture Black’s Queen on d5. However, had White captured the Queen, Black could have checkmated White by using his Rook on f6 to capture White’s Rook on f1, supported by the Bishop on h3.

Instead of capturing Black’s Queen, had White used his Rook on f1 to capture Black’s Rook on f6, Black could have checkmated White by moving the Queen from d5 to g2, again supported by the Bishop on h3. In the actual game, after thinking for 12minutes, White moved his Rook from c5 to c8, checking Black’s King on h8. Black simply moved his King to h7, and White immediately resigned.

Post-game analysis revealed, however, that on move 30 White could have escaped checkmate as follows: by moving his Queen to e8, checking Black’s King; after Black moved his King to h7, moving the Queen to g6, again checking Black’s King, and offering to sacrifice the Queen – a double exclamation mark move, leading to 3 possible lines.

Line 1: Had Black’s King accepted the sacrifice and captured White’s Queen on g6, White would have replied by using his Rook on f1 to capture Black’s Rook on f6, again checking Black’s King. After Black’s King recaptured White’s Rook on f6, White’s remaining Rook on c5 would have captured Black’s Queen on d5, eliminating both of Black’s checkmate threats, and leaving White with material and positional advantages and an eventual won game.

Line 2: Alternatively, had Black’s Rook on f6, instead of Black’s King, captured White’s Queen on g6, White’s remaining Rook on c5 would have captured Black’s Queen on d5, again eliminating both of Black’s checkmate threats, and leaving White with material and positional advantages and an eventual won game.

Line 3: Finally, instead of accepting White’s Queen sacrifice offer on g6, had Black’s King simply moved out of check back to h8, or to g8, White would have moved his Queen back to e8, checking Black’s King again, causing Black’s King to move back to h7 again, leading to White moving his Queen back to g6 again, checking Black’s King again, and so on, eventually leading to a draw by threefold repetition of position (unless Black unfavourably deviated to Line 1 or Line 2). Line 3, a forced draw, would have been the best option for Black.

In all 3 Lines White could have escaped checkmate. Even a Grandmaster can sometimes miss a move that avoids checkmate – and even after thinking for 12 minutes! BN