In the 13th game of the 1985 kasparov - Karpov World Match, the opposite-colour bishops suggest that a draw is likely. But nevertheless the pawn at b6 seems doomed, and the white bishop is stronger than Black’s … Dos this mean that all is not clear? Black to play.

This puzzle has been extracted from the excellent book The art of defence written by Lyev Polugayevsky and Iakov Damsky