A Third Mate In Four

White Moves And Wins.

On the back row, Black's King has a mere two squares - h7 and h8 - to play with, but there's also refuge at g7. White sniffs the danger and moves in with his own King.

1. Kf7 Kh8
2. Ng6+ Kh7
3. Nf8+ Kh8
4. Bf6 mate
(1-0)

(source: Pandolfini's EndGame Course)