Lesson
White to move. Main line: 1. Kf6 Kb5 2. Ke7 Kc5 3. Ke6 Kb4 4. Kxd6 Kc4
1.Kf6! begins the winning route. White does not rush to the pawn; the king chooses a square that preserves the favorable opposition as Black approaches from the queenside.
After 1...Kb5 2.Ke7 Kc5 3.Ke6, Black’s king cannot both guard d6 and oppose the white king. The move 3...Kb4 abandons the pawn, and 4.Kxd6 reaches a winning king-and-pawn ending.
This type of mutual-zugzwang geometry is often called the trébuchet. The practical method is to identify corresponding squares: whenever the defender occupies one square, the attacker must answer with the paired square that preserves the invasion route.