Checkmate
Two bishops on intersecting diagonals checkmate a king obstructed by its own pieces.
Two bishops slice across the board on intersecting diagonals to checkmate the king. One bishop delivers the check while the other cuts off the king's escape squares, usually taking advantage of friendly pieces that block the king's remaining flight paths.
Starting Position (FEN): 2kr4/p2p1ppp/1pp5/8/5B2/8/4B3/7K w - - 0 1
Move Sequence: Ba6#
Explanation: Two bishops slice across the board on intersecting diagonals to checkmate the king. One bishop delivers the check while the other cuts off the king's escape squares, usually taking advantage of friendly pieces that block the king's remaining flight paths.
Starting Position (FEN): 2kr4/pp1p1ppp/2p5/8/5B2/8/2Q1B3/7K w - - 0 1
Move Sequence: Qxc6+ bxc6 Ba6#
Explanation: The pattern very frequently appears after a brilliant queen sacrifice on c6 (or f3 for Black) that shatters the pawn shield and opens the mating diagonals.
Starting Position (FEN): 7k/8/3b4/5b2/8/1PP5/P2P1PPP/2KR4 b - - 0 1
Move Sequence: Ba3#
Explanation: The same twin-bishop geometry works just as well when Black attacks a queenside-castled white king.
Boden’s Mate was named after Samuel Boden, who famously played the pattern in an 1853 game. It is a recurring tactical danger for players who castle queenside and rely too heavily on the c-pawn for defense.
See also:Sacrifice·Discovered attack