Reciprocal Zugzwang: One Tempo Draws

Watch the method: press play to see the winning idea run, or step through it move by move.

The same position can be a win or a draw depending only on whose move it is. That is the signature of a reciprocal zugzwang, and this f and h versus h pawn ending is a clean example.

Ke2 or nothing. The tablebase is blunt: Ke2 draws, and every other legal move loses. Ke1, Kf1, Kg1, Kg2, h3 and h4 all hand Black the win. There is no margin here at all.

Corresponding squares, not a corner. The defense is not a run for the h1 corner, which loses outright. It is a correspondence: your king shuffles between e2, f2 and f3, and each black king move has exactly one white answer. The main line is Ke2 Ke4, Kf2 h4, Ke2 h3, Kf2 Kd3, Kf3 Kd2, Kf2, and Black is out of ways in.

Do not touch the pawn. Pushing h3 or h4 does not gain a tempo, it loses the game. The move is a reciprocal zugzwang and it has to be spent on Ke2, the corresponding square. In the mirror position, where Black has the move, Black's entire plan is to freeze that h2-pawn with ...h4 and ...h3 and then squeeze you in zugzwang.

In this drill you defend the exact position that loses with the roles reversed. Recognize which side of the zugzwang you are on, find Ke2, and hold the correspondence.