Training notebook · Endgames
Opposite-coloured bishop endings: find the blockade, not a slogan
Opposite-coloured bishops often offer defensive resources, but extra passers and king access still matter. Test a blockade against the attacker’s pawn breaks.
Different colours change the defence
When bishops travel on different square colours, one bishop cannot directly challenge the other's diagonal control. That can let a defender hold a blockading square and protect pawns even while down material. It explains many resilient endings, but it does not make every opposite-coloured bishop position drawn.
First check whether other pieces remain. With rooks or queens still present, an attack on squares the defending bishop cannot cover can be dangerous. Even in a pure bishop ending, widely separated passers, an active king or a successful pawn break may defeat an apparently comfortable blockade.
Identify what must never change
A defensive plan should name the critical squares and the pawn structure that keeps them secure. If the king must guard one passer and the bishop must stop another, calculate whether they can maintain those jobs after a pawn sacrifice. Do not allow a breakthrough just to keep the material count unchanged.
For the attacker, look for two problems that the same defensive setup cannot solve. A king invasion may make a second passer more useful than immediately advancing the first. Before sacrificing a pawn to open a path, verify that your bishop and king can actually use the new squares.
Practise the blockade from both sides
Choose a verified opposite-coloured-bishop exercise. Play the defender first and write the squares you intend to hold. Test the attacker's pawn breaks, including a sacrifice that changes which colour the remaining pawns occupy. Stop whenever your bishop's defensive diagonal is interrupted.
Then take the attacking side and try to create a second entry point rather than pushing the same pawn repeatedly. Record whether the defender's king or bishop becomes overloaded. A failed winning attempt can still teach something precise if you can explain why the original blockade survives every plausible change.
A useful post-game diagnosis
If an opposite-coloured-bishop ending slipped away, locate the first change that made the defensive setup impossible. It might be a pawn exchange, a king departure or a diagonal blocked by your own pawn. The final promotion is usually less informative than that earlier structural decision.
For a later self-test, cover the result of the exercise and describe both sides' plans. The defender should have a clear holding mechanism, and the attacker should have a concrete target or acknowledge the lack of one. Replace the phrase 'opposite bishops draw' with an explanation of what can or cannot be changed on this board.
Count how many pawn moves the defender can safely allow before the structure changes. A blockade may hold against one push but fail after a second passer appears. Conversely, the attacker may have no safe break at all. This explicit count is more informative than judging the ending from the bishops' colours alone.
Put the practice into a routine
Where Brass Pawn fits
Brass Pawn includes an Opposite-coloured bishops drill. Use it to practise the specific defence offered there; the built-in example does not determine the result of all opposite-coloured bishop endings.