Killing the Reserve Tempo: f and h vs the h-Pawn

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

The line between a draw and a win in this ending is a single tempo, and the tempo lives on h2.

Steinitz's rule, turned against White. A pawn on its original square can move one square or two, which is a reserve move the defender can spend whenever he needs to pass the turn back to you. White's h2-pawn is that reserve, and while it is available the defense holds. Your first job is to destroy it.

...h4 and ...h3. Push the h-pawn twice. Once it lands on h3, White's h2-pawn is blocked for the rest of the game and White has no pawn move left anywhere on the board. Every turn now costs him a king move, which is exactly what zugzwang needs. Your own f-pawn, still back on f5, is the spare move you keep for yourself.

The breakthrough. With White reduced to king moves, walk around him: ...Kd3, ...Kd2, ...Ke1, ...Kf1, ...Kg1 gets your king behind his. Then f4+ deflects the white king off the h2-pawn, ...Kxh2 wins it, and the f-pawn runs.

In this drill you have the move and therefore the win, but the path is long. Freeze the reserve tempo first, keep yours, and only then start the king march.