A. Trotsky, 1924
White to play and win
White to play and win
1.f6!
White forces the black king back as black has to go after the pawn.
1...Kd6 2.Bxd4 Nd2+
2...e5 3.Bxe5+ and black cannot take the bishop since the pawn would promote.
3.Ke2 Ne5 4.Be5+!
Again the bishop cannot be taken. This intermezzo is important since white needs to control the g3-square before they attack the knight with Ke3. For example: 4.f7? Ke7 5.Ke3 Ng3 (Not 5...Ng5 6.Bf6+!) and white isn't able to save the f-pawn.
4...Kd7 5.f7 Ke7 6.Ke3 Ng5 7.Bf6+! +-
White wins the knight or promotes the pawn.