Opposite-colored bishops

Opposite-colored bishops describes a position where each side has one bishop, but the bishops travel on different colors. White’s bishop is on light squares; Black’s on dark, or vice versa. The bishops can never directly interact — they pass each other without ever attacking the same square.

In endgames, opposite-colored bishops are famously drawish. An extra pawn, or even two, is often insufficient to win, because the defender’s bishop can sit on the squares the pawns need to cross. A passed pawn that travels on a square of one color cannot be supported by a bishop of the other color and can be blockaded indefinitely. Many positions with material advantages of two pawns are theoretical draws.

In middlegames, the same color disjunction produces the opposite effect. An attacker with an opposite-colored bishop has an extra piece on the attacking side — there is no defender on those squares. Opposite-colored bishop middlegames are among the sharpest in chess; the side with the initiative often wins, and the defender’s bishop is essentially a spectator.

The middlegame-versus-endgame contrast is the bishops’ defining strategic feature. A player with a worse position in the middlegame can sometimes steer toward an opposite-color bishop endgame as a saving resource. A player with a winning attack in the middlegame must convert before the position simplifies into the bishops’ drawn shape.