%TITLE Longest mate in King and Bishop versus King and Bishop endgame: an endgame analysis by Joe Leslie-Hurd
%HEADING Longest mate in King and Bishop versus King and Bishop endgame
%SUBHEADING Mate in 1
%FOOTER An <a href="http://www.gilith/chess/endgames">endgame analysis</a> by <a href="http://www.gilith.com/">Joe Leslie-Hurd</a> on 16 February 2005.

[Event "Endgame analysis: longest mate in King and Queen versus King and Queen"]
[Site "Oxford ENG"]
[Date "2005.02.16"]
[Round "-"]
[White "Perfect"]
[Black "Perfect"]
[Result "1-0"]
[Time "06:08:15"]
[Annotator "Joe Leslie-Hurd"]
[WhiteType "program"]
[BlackType "program"]
[SetUp "1"]
[FEN "1Q1K2kq/8/8/8/8/8/8/8 w - - 0 1"]

{Mate in 13 with Ke7+. Worse are Kc7+, Kc8, Kd7+, Ke8, Qa7, Qa8, Qb1, Qb2, Qb3+, Qb4, Qb5, Qb6, Qb7, Qc7, Qc8, Qd6, Qe5, Qf4, Qg3+ and Qh2 which throw away the win.}
1. Ke7+ {White mates in 12 after Kh7. Worse is Kg7 when White mates in 8.}
1... Kh7 {Mate in 12 with Qb1+. Worse are Qh2+ with mate in 13, and Kd6, Kd7, Ke6, Kf7, Qa7, Qa8, Qb2, Qb3, Qb4, Qb5, Qb6, Qb7, Qc7, Qc8, Qd6, Qd8, Qe5, Qe8, Qf4, Qf8, Qg3, Qg8+ and Qxh8+ which throw away the win.}
2. Qb1+ {White mates in 11 after Kg8 and Kh6. Worse is Kg7 when White mates in 10.}
2... Kg8 {Mate in 11 with Qb3+. Worse are Qa2+ with mate in 12, Qb8+ with mate in 13, and Kd6, Kd7, Kd8, Ke6, Ke8, Qa1, Qb2, Qb4, Qb5, Qb6, Qb7, Qc1, Qc2, Qd1, Qd3, Qe1, Qe4, Qf1, Qf5, Qg1+, Qg6+, Qh1 and Qh7+ which throw away the win.}
3. Qb3+ {White mates in 10 after Kh7. Worse is Kg7 when White mates in 8.}
3... Kh7 {Mate in 10 with Qd3+. Worse are Qc2+ and Qh3+ with mate in 11, Qb1+ with mate in 12, and Kd6, Kd7, Ke6, Kf7, Qa2, Qa3, Qa4, Qb2, Qb4, Qb5, Qb6, Qb7, Qb8, Qc3, Qc4, Qd1, Qd5, Qe3, Qe6, Qf3, Qf7+, Qg3 and Qg8+ which throw away the win.}
4. Qd3+ {White mates in 9 after Kh6. Worse are Kg7 when White mates in 8, and Kg8 when White mates in 7.}
4... Kh6 {Mate in 9 with Qh3+. Worse are Kd6, Kd7, Ke6, Kf7, Qa3, Qa6+, Qb1, Qb3, Qb5, Qc2, Qc3, Qc4, Qd1, Qd2+, Qd4, Qd5, Qd6+, Qd7, Qd8, Qe2, Qe3+, Qe4, Qf1, Qf3, Qf5, Qg3, Qg6+ and Qh7+ which throw away the win.}
5. Qh3+ {White mates in 8 after Kg5 and Kg7. Worse is Kg6 when White mates in 6.}
5... Kg5 {Mate in 8 with Qxh8. Worse are Kd6, Kd7, Ke6, Kf7, Qa3, Qb3, Qc3, Qc8, Qd3, Qd7, Qe3+, Qe6, Qf1, Qf3, Qf5+, Qg2+, Qg3+, Qg4+, Qh1, Qh2, Qh4+, Qh5+, Qh6+ and Qh7 which throw away the win.}
6. Qxh8 {White mates in 7 after Kf4 and Kg4. Worse are Kf5 when White mates in 5, and Kg6 when White mates in 4.}
6... Kf4 {Mate in 7 with Ke6 and Qc3. Worse are Kd6, Kd7, Kf6, Kf7, Qa1, Qb2, Qc8, Qd4+, Qd8, Qe8, Qf6+, Qg7, Qh1, Qh2+, Qh3, Qh4+, Qh5, Qh6+ and Qh7 with mate in 8, Kd8, Ke8, Kf8, Qa8, Qb8+, Qf8+ and Qg8 with mate in 9, and Qe5+ which throws away the win.}
7. Qc3 {White mates in 6 after Ke4. Worse are Kf5, Kg4 and Kg5 when White mates in 5.}
7... Ke4 {Mate in 6 with Ke6 and Kf6. Worse are Kd6, Kd7, Ke8, Kf7 and Qd2 with mate in 7, Kd8, Kf8, Qa1, Qa3, Qa5, Qb2, Qb3, Qb4+, Qc1, Qc2+, Qc4+, Qc5, Qc6+, Qe1+, Qf6, Qg3 and Qh3 with mate in 8, Qc7, Qc8, Qg7 and Qh8 with mate in 9, and Qd3+, Qd4+, Qe3+, Qe5+ and Qf3+ which throw away the win.}
8. Kf6 {White mates in 5 after Kd5. Worse is Kf4 when White mates in 4.}
8... Kd5 {Mate in 5 with Qb4. Worse are Kf5 with mate in 6, Ke7, Kf7, Kg5, Kg6, Kg7, Qd2+, Qd3+ and Qe3 with mate in 7, Qa1, Qa3, Qa5+, Qb2, Qb3+, Qc1, Qc2, Qc7, Qc8, Qe1, Qe5+, Qf3+, Qg3 and Qh3 with mate in 8, and Qc4+, Qc5+, Qc6+ and Qd4+ which throw away the win.}
9. Qb4 {White mates in 4 after Kc6.}
9... Kc6 {Mate in 4 with Ke6. Worse are Ke5 with mate in 5, Ke7, Kf5, Kf7, Kg5, Kg6, Kg7, Qa5, Qc3+ and Qc4+ with mate in 6, Qa3, Qa4+, Qb2, Qb3, Qd2, Qd4, Qe1, Qe4+, Qf4, Qg4 and Qh4 with mate in 7, Qb1, Qb8, Qe7 and Qf8 with mate in 8, and Qb5+, Qb6+, Qb7+, Qc5+ and Qd6+ which throw away the win.}
10. Ke6 {White mates in 3 after Kc7.}
10... Kc7 {Mate in 3 with Qb5. Worse are Kd5 with mate in 4, Ke5, Ke7, Kf5, Kf6, Kf7, Qa3, Qa4, Qa5+, Qb1, Qb2, Qb3, Qc3+, Qc4+, Qc5+, Qd4, Qd6+ and Qe7+ with mate in 5, Qd2, Qe1, Qe4, Qf4+, Qf8, Qg4 and Qh4 with mate in 6, and Qb6+, Qb7+ and Qb8+ which throw away the win.}
11. Qb5 {White mates in 2 after Kc8. Worse is Kd8 when White mates in 1.}
11... Kc8 {Mate in 2 with Kd6. Worse are Kd5, Ke5, Ke7, Kf5, Kf6, Qb1, Qb2, Qb3, Qb4 and Qd7+ with mate in 4, Kf7, Qa4, Qa5, Qa6+, Qc4+, Qc5+, Qc6+, Qd3, Qd5, Qe2, Qe5, Qe8+, Qf1, Qf5, Qg5 and Qh5 with mate in 5, and Qb6, Qb7+ and Qb8+ which throw away the win.}
12. Kd6 {White mates in 1 after Kd8.}
12... Kd8 {Mate in 1 with Qb8# and Qd7#. Worse are Qa4, Qb7, Qc4 and Qd5 with mate in 2, Qa5+, Qa6, Qb1, Qb2, Qb3, Qb4, Qb6+, Qc5, Qd3, Qe2, Qe5, Qf1, Qf5, Qg5+ and Qh5 with mate in 3, Ke5 and Ke6 with mate in 4, Kc6 and Kd5 with mate in 5, Kc5 with mate in 7, and Qc6 and Qe8+ which throw away the win.}
13. Qd7# {Checkmate.} 1-0
