Find the decisive blow (difficulty 1500)

87654321 abcdefgh

White to move

Show solution
87654321 abcdefgh
  1. f6–d8 key move
  2. e8–d8
  3. d3–d4

What makes it

The bishop strikes, 3 points of material given up, and the attack wins. It calculates 18 plies deep. At 1500, punishing to calculate.