Figure[White to move]

Loosening the Pinning Square.

Now for a couple of examples where the basics of a pin are in place but the needed square is guarded by your opponent. We need not belabor the techniques here since they are familiar from earlier work on loosening a forking square, but a brief look will help make the patterns more visually familiar. In the frame to the left White sees an obvious kernel of a pin: Black’s queen and king are on the same diagonal. White’s light-squared bishop is available, can reach the pinning square—d5—in one move, and will have protection there from its queen. But White sees that the pinning square is protected. Indeed, the square is attacked twice by White but protected twice, by Black’s queen and knight. What to do? Exchange away one of the guards. White plays BxN; if Black recaptures with a7xB, the exchange has left the pinning square with only one Black defender. Now White safely can play Bd5, pinning the queen with support from White’s own queen on d1. Black’s queen is lost.