Longest mate in King and 2 Bishops versus King endgame

Mate in 19

Also available in PGN notation.

White to move
Mate in 19 with Bc2, Bc6, Bd1, Bd7 and Be8. Worse are Ba5+, Bb3, Bb5, Bb6, Bc7, Be7+, Bf6, Bg5, Bh4, Kg1, Kg2 and Kh2 which throw away the win.
1. Bc6
White mates in 18 after Kc5. Worse are Kb3, Kc3 and Kc4 when White mates in 15, and Ka3 when White mates in 14.
1... Kc5
Mate in 18 with Ba8, Bb7 and Bf3. Worse are Bd7, Be4, Be8 and Bg2 with mate in 19, Ba4 with mate in 20, and Ba5, Bb5, Bb6+, Bc7, Bd5, Be7+, Bf6, Bg5, Bh4, Kg1, Kg2 and Kh2 which throw away the win.
2. Bb7
White mates in 17 after Kb5, Kd4 and Kd6. Worse are Kb4 and Kc4 when White mates in 16.
2... Kd6
Mate in 17 with Bb6, Kg2 and Kh2. Worse are Ba5, Ba8, Bf3, Bg5, Bh4 and Kg1 with mate in 18, Ba6, Bc8, Be4, Bf6 and Bg2 with mate in 19, and Bc6, Bc7+, Bd5 and Be7+ which throw away the win.
3. Kg2
White mates in 16 after Kc5, Kd7 and Ke5. Worse is Ke6 when White mates in 15.
3... Kd7
Mate in 16 with Bb6. Worse are Ba5, Bf6, Bg5 and Bh4 with mate in 17, and Ba6, Ba8, Bc6+, Bc7, Bc8+, Bd5, Be4, Be7, Bf3, Kf1, Kf2, Kf3, Kg1, Kg3, Kh1, Kh2 and Kh3 which throw away the win.
4. Bb6
White mates in 15 after Kd6 and Ke6. Worse are Ke7 and Ke8 when White mates in 14.
4... Kd6
Mate in 15 with Be4, Kf3, Kg3 and Kh3. Worse are Ba8, Bd4, Bf3, Kf2 and Kh2 with mate in 16, Ba5, Ba6, Ba7, Bd8, Be3, Bf2, Bg1, Kf1, Kg1 and Kh1 with mate in 17, Bc8 with mate in 18, and Bc5+, Bc6, Bc7+ and Bd5 which throw away the win.
5. Kf3
White mates in 14 after Ke5. Worse are Kd7, Ke6 and Ke7 when White mates in 13.
5... Ke5
Mate in 14 with Be3, Be4 and Kg4. Worse are Ba6, Ba7, Ba8, Bc5, Bc6, Bc7+, Bf2, Bg1, Ke3 and Kg3 with mate in 15, Ba5, Bc8, Bd8, Ke2, Kf2 and Kg2 with mate in 16, and Bd4+ and Bd5 which throw away the win.
6. Be4
White mates in 13 after Kd6, Ke6 and Kf6.
6... Kd6
Mate in 13 with Kf4. Worse are Ke3 with mate in 14, Ba5, Ba7, Ba8, Bb7, Bd4, Bd8, Be3, Bf2, Bg1, Ke2, Kf2, Kg2, Kg3 and Kg4 with mate in 15, Bb1, Bc2, Bd3, Bf5, Bg6 and Bh7 with mate in 16, and Bc5+, Bc6, Bc7+ and Bd5 which throw away the win.
7. Kf4
White mates in 12 after Ke6. Worse are Kd7 when White mates in 11, and Ke7 when White mates in 10.
7... Ke6
Mate in 12 with Bc5. Worse are Ba5, Ba7, Ba8, Bb7, Bc6, Bc7, Bd4, Bd8, Be3, Bf2, Bf3, Bg1, Bg2, Bh1, Ke3 and Kf3 with mate in 14, Bb1, Bc2, Bd3, Bf5+, Bg6, Bh7, Kg3, Kg4 and Kg5 with mate in 15, and Bd5+ which throws away the win.
8. Bc5
White mates in 11 after Kd7. Worse are Kf6 and Kf7 when White mates in 10.
8... Kd7
Mate in 11 with Ke5. Worse are Bd5, Bf3 and Kf5 with mate in 12, Ba3, Ba8, Bb4, Bb6, Bb7, Bf8, Bg2, Bh1, Ke3, Kf3, Kg3, Kg4 and Kg5 with mate in 13, Ba7, Bd4, Be3, Bf2 and Bg1 with mate in 14, Bd3 with mate in 15, Bb1, Bc2, Bf5+, Bg6 and Bh7 with mate in 16, and Bc6+, Bd6 and Be7 which throw away the win.
9. Ke5
White mates in 10 after Kc7 and Kd8. Worse are Kc8 and Ke8 when White mates in 9.
9... Kc7
Mate in 10 with Bd5 and Ke6. Worse are Bf3, Kd4 and Kd5 with mate in 11, Ba3, Ba7, Ba8, Bb4, Bc2, Bd3, Bd4, Bd6+, Be3, Be7, Bf2, Bf5, Bf8, Bg1, Bg2, Bg6, Bh1, Kf4, Kf5 and Kf6 with mate in 12, Bb1 and Bh7 with mate in 13, and Bb6+, Bb7 and Bc6 which throw away the win.
10. Ke6
White mates in 9 after Kc8. Worse are Kb8 and Kd8 when White mates in 8.
10... Kc8
Mate in 9 with Bb6 and Kd6. Worse are Bb4, Bc6, Bd3, Bd6, Bf5 and Bg6 with mate in 10, Ba3, Ba7, Ba8, Bb1, Bc2, Bd4, Bd5, Be3, Be7, Bf2, Bf3, Bf8, Bg1, Bg2, Bh1, Bh7, Kd5, Ke5 and Ke7 with mate in 11, Kf5 and Kf6 with mate in 12, Kf7 with mate in 13, and Bb7+ which throws away the win.
11. Kd6
White mates in 8 after Kd8. Worse is Kb8 when White mates in 6.
11... Kd8
Mate in 8 with Bd5, Bg6 and Kc6. Worse are Bb6+, Bb7, Bc6, Bd4 and Be3 with mate in 9, Ba3, Bb1, Bb4, Bc2, Bd3, Bf2, Bf3, Bf5, Bg2 and Bh7 with mate in 10, Ba7, Bg1, Kd5, Ke5 and Ke6 with mate in 11, and Ba8 and Bh1 with mate in 12.
12. Kc6
White mates in 7 after Ke8. Worse is Kc8 when White mates in 5.
12... Ke8
Mate in 7 with Bd5 and Bg6+. Worse are Kd5 and Kd6 with mate in 11, Ba3, Bb1, Bb4, Bc2, Bd3, Bd4, Bd6, Be3, Bf2 and Kc7 with mate in 12, Bb6 and Bf5 with mate in 13, Ba7, Bf3, Bg1, Bg2, Bh1, Bh7, Kb5, Kb6 and Kb7 with mate in 14, and Be7 and Bf8 which throw away the win.
13. Bd5
White mates in 6 after Kd8.
13... Kd8
Mate in 6 with Bf7. Worse are Ba2, Ba3, Bb3, Bb4, Bc4, Bd6, Be4, Be6, Bf3, Bf8, Bg2, Bg8, Bh1, Kb6, Kb7 and Kd6 with mate in 8, Kb5 with mate in 9, Bd4 with mate in 11, Ba7, Bb6+, Be3, Bf2 and Bg1 with mate in 12, and Be7+ which throws away the win.
14. Bf7
White mates in 5 after Kc8.
14... Kc8
Mate in 5 with Be7. Worse are Ba2, Ba3, Ba7, Bb3, Bb4, Bb6, Bc4, Bd4, Bd5, Bd6, Be3, Be6+, Be8, Bf2, Bf8, Bg1, Bg6, Bg8 and Bh5 with mate in 7, Kb6 with mate in 8, Kb5 and Kd6 with mate in 9, and Kd5 with mate in 10.
15. Be7
White mates in 4 after Kb8.
15... Kb8
Mate in 4 with Kb6. Worse are Bc4 with mate in 5, Ba2, Bb3, Bb4, Bc5, Bd5, Bd6+, Be6, Bf6, Bg5, Bg6, Bg8, Bh4 and Bh5 with mate in 6, Ba3, Bd8, Be8 and Bf8 with mate in 7, Kb5 with mate in 8, Kc5, Kd6 and Kd7 with mate in 9, and Kd5 with mate in 10.
16. Kb6
White mates in 3 after Ka8 and Kc8.
16... Kc8
Mate in 3 with Be6+. Worse are Be8 and Kc6 with mate in 5, Ba3, Bb4, Bc5, Bd6 and Bf8 with mate in 8, Bb3, Bc4, Bd5 and Kc5 with mate in 9, Ba2, Bf6, Bg5, Bg8, Bh4 and Kb5 with mate in 10, Ka5, Ka6 and Ka7 with mate in 11, Bg6 with mate in 16, Bh5 with mate in 18, and Bd8 which throws away the win.
17. Be6+
White mates in 2 after Kb8.
17... Kb8
Mate in 2 with Bd6+. Worse are Ba2, Ba3, Bb3, Bb4, Bc4, Bc5, Bd5, Bd7, Bd8, Bf5, Bf6, Bf7, Bf8, Bg4, Bg5, Bg8, Bh3 and Bh4 with mate in 4, Kc6 with mate in 6, Ka6 and Kb5 with mate in 8, Ka5 and Kc5 with mate in 9, and Bc8 which throws away the win.
18. Bd6+
White mates in 1 after Ka8.
18... Ka8
Mate in 1 with Bd5#. Worse are Ba3, Bb4, Bc5, Be7 and Bf8 with mate in 3, Kc7 with mate in 4, Kc6 with mate in 5, Ka5, Kb5 and Kc5 with mate in 7, and Ba2, Bb3, Bb8, Bc4, Bc7, Bc8, Bd7, Be5, Bf4, Bf5, Bf7, Bg3, Bg4, Bg8, Bh2, Bh3 and Ka6 which throw away the win.
19. Bd5#
Checkmate.
1-0


An endgame analysis by Joe Leslie-Hurd on 16 February 2005.