Zugzwang: When Having to Move Is the Problem

In chess you cannot pass. Usually that is an advantage, because a move lets you improve. But in some positions every piece is already on its best square, and any move gives something away: a key square, a pawn, or a defensive post. The side to move is then in zugzwang.

Zugzwang is most common in endgames, where there are few pieces and few useful moves. In king and pawn endings it decides almost everything. When the pawns are blocked and only the kings can move, whoever has to step aside often loses.

The most important zugzwang tool is the opposition: kings facing each other with one square between them. The side not to move "has the opposition", because the other king must give way, either letting the enemy king forward or abandoning a pawn. Many endgames come down to reaching this setup with the right side to move.

Before trading into a pawn ending, count the spare pawn moves (tempo moves) each side has. If your opponent runs out of pawn moves first, their king will be forced to retreat.

First freeze the opponent's pawns, so their only moves are with the king or with pieces tied to defence. Then improve your position until every enemy move concedes something. If you need to lose a tempo to hand the move back, look for a spare pawn move or a triangle manoeuvre with the king.

Simplification is a common way in: trading the last pieces into a king and pawn ending where the opponent has to move and has nothing useful to do. Endgames you misplay in your own games are the best place to practise this.