Blocked Pawns and Their Key Squares

A blocked pawn cannot advance, but it can still be won, and a won pawn wins games. When the base of a pawn chain is jammed against an enemy pawn, you attack it by reaching one of its key squares first.

Key squares for a blocked pawn. They sit on the pawn's own rank, three files to its left and three to its right. A king that occupies one wins the pawn, whoever is to move. The fight is a pure race, so count the moves for each king before you set off.

Winning the pawn is not always winning the game. Reaching a key square only wins the pawn. If the position left behind is a drawn king and pawn ending, or a bare rook pawn, the capture is worthless. Here the surviving b-pawn still wins, so the race is worth running.

In this drill the enemy king will try to reach the pawn first. Count the routes, take the shortest one that also shoulders him off, and collect the pawn.