Opposite-coloured bishops: when being a pawn up doesn't mean winning

Nothing humbles a confident 'I'm winning, I'm up a pawn' faster than opposite-coloured bishops. It's one of chess's cleanest paradoxes: the exact same imbalance is famously drawish in a pure endgame and famously dangerous for the attacker when other pieces are still on the board. Knowing which regime you're in changes everything about how you should play the position.

Why the pure endgame is so drawish

Bishops on opposite colours can never occupy the same square, challenge each other, or trade themselves off. That means the defending side can build a blockade on the one colour the attacker's bishop can never touch — and just sit there. Two extra pawns, even three, often aren't enough to break through if the defender's king and bishop can reach the safe colour in time. This is why grandmasters routinely offer draws from positions that look, on the scoresheet, completely lost.

Why the middlegame is the opposite

Take the queens and rooks off and everything changes: with major pieces still on, opposite-coloured bishops favour the attacker, not the defender. The attacking bishop operates on a colour complex the defender's own bishop can never help guard — so an attack on that colour has, in effect, one fewer defender than the material count suggests. Sacrifices that 'shouldn't' work often do, because the bishop that should be defending simply cannot.

The practical rule

If you're worse but heading for a pure opposite-bishop endgame, steer for it — it may well be a draw regardless of the pawn count. If you're attacking with queens or rooks still on the board and you have the bishop the defender's own bishop can't oppose, keep the pieces on and press: the imbalance is working for you, not against you.

Same two bishops, same opposite colours, two completely different verdicts — always ask which phase of the game you're actually in before you judge the position by material alone.