King + Pawn vs King: Key Squares

Every pawn owns three KEY SQUARES — two ranks ahead of it, on its file and both neighbors (highlighted here for the e4-pawn: d6, e6, f6).

The theorem: if your king reaches ANY key square, the pawn promotes BY FORCE — opposition tricks, tempo, none of it matters anymore. The whole K+P endgame is a race for these three squares.