Lesson
White to move. Main line: 1. Kf7 Kh7 2. Kf8 Kh8
White has a light-squared bishop, but the h-pawn promotes on h8, a dark square. That color mismatch is decisive: the bishop can never drive the black king out of the corner that matters.
Black’s entire defensive plan is Kh7–h8 and back again when needed. If White pushes h7 while the king sits on h8, the pawn is blocked; if the white king approaches, there is no legal way to take the corner without stalemating or abandoning the pawn.
This is the “wrong bishop” exception to the usual rule that bishop and rook pawn beat a lone king. Before trading into such an ending, check the color of the bishop against the promotion square. One color comparison can save—or cost—half a point.