Find the decisive blow (difficulty 1530)

87654321 abcdefgh

White to move

Show solution
87654321 abcdefgh
  1. g7–h5 key move
  2. g8–h8
  3. h5–f6

What makes it

It starts with a knight move and forces mate in 12. The blow comes from a discovered attack — one piece moves, another fires. The forced line runs 23 plies.