Wrong-colored bishop — what it means in chess
A rook-pawn plus a bishop that doesn't control the promotion square; often only a draw.
A rook-pawn plus a bishop that doesn't control the promotion square; often only a draw.
[[board startfen="k7/8/PK6/8/8/8/3B4/8 b - - 0 1" pgn="Kb8 a7+ Ka8" caption="A full extra bishop and a pawn one step from promotion — and the game is a dead draw. The dark-squared bishop can never touch a8, and the black king never leaves the corner." notes="White has an extra bishop and a far-advanced pawn. The catch: the promotion square a8 is a light square, and the bishop lives on dark squares. It can never attack a8, never evict a king that sits there, never help. Black heads for the corner — the only plan, and a sufficient one. The pawn advances with check, as far as it will ever go. The king arrives on a8, and the position is over. Every bishop move now stalemates the cornered king, and stepping the White king away only invites Kxa7, trading the pawn for a bare-bishop draw. A piece up, and both roads end at the same half point."]]
The wrong-colored bishop (or wrong rook pawn) is the endgame's most famous exception: bishop plus rook pawn against a bare king is a draw whenever the bishop does not control the pawn's promotion corner and the defending king can reach it. The position above is the entire proof: White owns an extra piece and a pawn on the seventh, and there is no win on the board. Both endings sit in plain view — every bishop move stalemates the cornered king, and if the White king abandons the pawn instead, Black captures it and king plus bishop against a bare king is a dead draw. Two roads, one half point, and disturbing the corner is beyond a dark-squared bishop's powers forever.
The Endgame Society glossary defines more than 240 chess terms — rules, notation, tactics, strategy, pawn structures, endgames, and openings — in language a beginner can act on rather than dictionary shorthand.