Find the decisive blow (difficulty 945)

87654321 abcdefgh

White to move

Show solution
87654321 abcdefgh
  1. g5–e6 key move
  2. g6–f7
  3. g4–g7

What makes it

A knight move forces mate in three. A piece slips off the line and the attack opens up behind it. Rated 945 — a warm-up.