Find the decisive blow (difficulty 1650)

87654321 abcdefgh

White to move

Show solution
87654321 abcdefgh
  1. e6–e8 key move
  2. g8–e8
  3. d6–e8

What makes it

The win is mate in 20, paid for with a 4-point sacrifice. One move, several targets — the fork leaves no defence. The forced line runs 39 plies.