Longest mate in King, Rook and Bishop versus King endgame

Mate in 16

Also available in PGN notation.

White to move
Mate in 16 with Ra3 and Rf1. Worse are Rb3, Rc3, Rf2, Rf4+, Rf6, Rf7, Rf8, Rg3 and Rh3 with mate in 17, and Bb2, Bb8, Bc3, Bc7, Bd4, Bd6, Bf4, Bf6, Bg3, Bg7, Bh2, Bh8, Ka2, Kb1, Kb2, Rd3, Re3+ and Rf5 which throw away the win.
1. Rf1
White mates in 15 after Kxe5. Worse are Kd5 when White mates in 11, and Kd3 and Ke3 when White mates in 9.
1... Kxe5
Mate in 15 with Kb2 and Re1+. Worse are Ka2, Kb1, Rb1, Rc1, Rd1, Rg1 and Rh1 with mate in 16, Rf2, Rf3, Rf7 and Rf8 with mate in 17, and Rf4, Rf5+ and Rf6 which throw away the win.
2. Re1+
White mates in 14 after Kd4, Kd5, Kf4 and Kf6. Worse are Kd6 and Kf5 when White mates in 13.
2... Kd4
Mate in 14 with Kb2. Worse are Ka2, Kb1 and Re8 with mate in 15, Rb1, Rc1, Rd1+, Re6, Re7, Rf1, Rg1 and Rh1 with mate in 16, Re2 with mate in 17, and Re3, Re4+ and Re5 which throw away the win.
3. Kb2
White mates in 13 after Kd3. Worse are Kc5 when White mates in 12, and Kc4 and Kd5 when White mates in 11.
3... Kd3
Mate in 13 with Kb3. Worse are Re8 with mate in 14, Ka2, Ka3, Kb1, Kc1, Ra1, Rb1, Rc1, Rd1+, Re5, Re6, Re7, Rf1, Rg1 and Rh1 with mate in 15, Ka1 with mate in 16, and Re2, Re3+ and Re4 which throw away the win.
4. Kb3
White mates in 12 after Kd2 and Kd4.
4... Kd4
Mate in 12 with Kb4. Worse are Kc2 with mate in 13, Ka3, Ka4, Kb2, Ra1, Rb1, Rc1, Rd1+, Re2, Re6, Re7, Re8, Rf1, Rg1 and Rh1 with mate in 14, Ka2 with mate in 15, and Re3, Re4+ and Re5 which throw away the win.
5. Kb4
White mates in 11 after Kd3 and Kd5.
5... Kd5
Mate in 11 with Kc3. Worse are Ka4, Ka5, Kb3, Kb5, Re2, Re3, Re7 and Re8 with mate in 13, Ka3, Ra1, Rb1, Rc1, Rd1+, Rf1, Rg1 and Rh1 with mate in 14, and Re4, Re5+ and Re6 which throw away the win.
6. Kc3
White mates in 10 after Kc5 and Kc6. Worse is Kd6 when White mates in 9.
6... Kc5
Mate in 10 with Rd1. Worse are Re5+ with mate in 11, Kd3, Re2, Re3, Re4, Re6 and Re8 with mate in 12, Kb3, Ra1, Rb1, Rc1, Re7, Rf1, Rg1 and Rh1 with mate in 13, and Kb2, Kc2 and Kd2 with mate in 14.
7. Rd1
White mates in 9 after Kb5. Worse are Kb6 when White mates in 8, and Kc6 when White mates in 7.
7... Kb5
Mate in 9 with Kd4 and Rd5+. Worse are Kb3, Rd2, Rd3, Rd6 and Rd8 with mate in 10, Kd3, Ra1, Rb1+, Rc1, Rd4, Rd7, Re1, Rf1, Rg1 and Rh1 with mate in 11, Kb2 and Kc2 with mate in 12, and Kd2 with mate in 13.
8. Kd4
White mates in 8 after Kb6 and Kc6. Worse are Kb4 when White mates in 7, Ka6 when White mates in 6, and Ka4 and Ka5 when White mates in 3.
8... Kc6
Mate in 8 with Kc4. Worse are Kc3 and Re1 with mate in 10, Ke5, Ra1, Rg1 and Rh1 with mate in 11, Ke3, Ke4, Rb1, Rc1+, Rd2, Rd3 and Rf1 with mate in 12, and Kd3 with mate in 13.
9. Kc4
White mates in 7 after Kb6. Worse are Kb7 when White mates in 6, and Kc7 when White mates in 5.
9... Kb6
Mate in 7 with Rd6+. Worse are Kb4, Kd5, Rd2, Rd3 and Rd4 with mate in 8, Ra1, Rb1+, Rc1, Rd5, Rd7, Rd8, Re1, Rf1, Rg1 and Rh1 with mate in 9, Kb3, Kc3 and Kd4 with mate in 10, and Kd3 with mate in 11.
10. Rd6+
White mates in 6 after Ka7, Kb7 and Kc7. Worse is Ka5 when White mates in 2.
10... Kb7
Mate in 6 with Kb5. Worse are Kb4, Kc5 and Kd5 with mate in 7, Kd4, Rd1, Rd2, Rd3 and Rd4 with mate in 8, Rd5, Rd7+, Rd8, Re6, Rf6, Rg6 and Rh6 with mate in 9, Kb3, Kc3 and Kd3 with mate in 10, and Ra6, Rb6+ and Rc6 which throw away the win.
11. Kb5
White mates in 5 after Kc7. Worse are Ka7 when White mates in 4, Kb8 when White mates in 3, and Ka8 and Kc8 when White mates in 2.
11... Kc7
Mate in 5 with Rd1, Rd2, Rd3, Rd4 and Rd5. Worse are Kc5 with mate in 6, Rc6+ with mate in 10, Ra6, Rb6, Re6, Rf6, Rg6 and Rh6 with mate in 11, and Ka4, Ka5, Ka6, Kb4, Kc4, Rd7+ and Rd8 which throw away the win.
12. Rd2
White mates in 4 after Kb7. Worse are Kb8 when White mates in 3, and Kc8 when White mates in 2.
12... Kb7
Mate in 4 with Rc2. Worse are Rd7+ with mate in 5, Kc5, Ra2, Rb2, Rd1, Rd3, Rd4, Rd5, Rd6, Rd8, Re2, Rf2, Rg2 and Rh2 with mate in 6, and Ka4, Ka5, Kb4 and Kc4 with mate in 8.
13. Rc2
White mates in 3 after Ka7 and Ka8. Worse is Kb8 when White mates in 2.
13... Ka7
Mate in 3 with Kc6. Worse are Rc7+ with mate in 4, Ka5, Kc5, Ra2+, Rb2, Rc1, Rc3, Rc4, Rc5, Rc6, Rc8, Rd2, Re2, Rf2, Rg2 and Rh2 with mate in 5, and Ka4, Kb4 and Kc4 with mate in 7.
14. Kc6
White mates in 2 after Ka8 and Kb8. Worse is Ka6 when White mates in 1.
14... Ka8
Mate in 2 with Kc7. Worse are Kb6, Ra2+, Rd2, Re2, Rf2, Rg2 and Rh2 with mate in 3, Rb2, Rc1, Rc3, Rc4 and Rc5 with mate in 4, Kb5 and Kc5 with mate in 5, Kd6 and Kd7 with mate in 6, and Kd5 with mate in 8.
15. Kc7
White mates in 1 after Ka7.
15... Ka7
Mate in 1 with Ra2#. Worse are Rc6 with mate in 2, Kc6, Rc1, Rc3, Rc4, Rc5, Rd2, Re2, Rf2, Rg2 and Rh2 with mate in 3, Kd6 with mate in 7, Rb2 with mate in 8, Kd7 with mate in 11, and Kc8 and Kd8 with mate in 12.
16. Ra2#
Checkmate.
1-0


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