I have a huge collection of chess problems that are solved

[Mish]

Here is a mate in 9 that took almost 8 hours to solve:
[d]2r1k3/6pr/p1nBP3/1p3p1p/2q5/2P5/P1R4P/K2Q2R1 w - - acn 3013537185; acs 27873; bm Rxg7; ce 32750; dm 9; id "ChestDB.3753"; pv Rxg7 Qxe6 Rxh7 Ne7 Bxe7 Qg6 Bc5 Qxh7 Qd6 Rxc5 Re2+ Re5 Rxe5+ Kf7 Re7+ Kf8 Qd8#;






?????


New game
2r1k3/6pr/p1nBP3/1p3p1p/2q5/2P5/P1R4P/K2Q2R1 w - - 0 1

Analysis by Rybka 2.3.2 mp :

1.Rxg7 Ne7
+- (8.67) Depth: 5 00:00:00
1.Rxg7 Ne7 2.Bxe7
+- (9.32) Depth: 6 00:00:00 39kN
1.Rxg7 Qxe6 2.Rxh7 f4 3.Qxh5+ Kd8 4.Bxf4
+- (12.69) Depth: 7 00:00:00 235kN
1.Rxg7 Qxe6 2.Rxh7 b4 3.Rh8+ Kf7 4.Qxh5+ Qg6
+- (12.71) Depth: 8 00:00:00 279kN
1.Rxg7 Qxe6 2.Rxh7 f4 3.Qxh5+ Kd8 4.Qg5+
+- (17.28) Depth: 9 00:00:01 742kN
1.Rxg7 Qxe6 2.Rxh7 Ne5 3.Bxe5 Kf8 4.Qxh5 Rd8 5.Rh8+ Ke7 6.Qh4+ Kd7
+- (17.48) Depth: 10 00:00:02 1521kN
1.Rxg7 Qxe6 2.Rxh7 Ne5 3.Bxe5 Rd8 4.Rh8+ Kf7 5.Qxd8
+- (20.23) Depth: 11 00:00:05 3464kN
1.Rxg7 Qxe6 2.Rxh7 Qe3 3.Bc5 Ne7 4.Bxe3 Rc7 5.Qxh5+ Kd8 6.Rd2+ Rd7 7.Bb6+ Kc8 8.Qe8+ Kb7 9.Rxd7+ Kxb6 10.Rdxe7 Ka5 11.Qd8+ Ka4 12.Rh4+ b4 13.cxb4 Kb5
+- (#16) Depth: 12 00:00:07 5817kN
1.Rxg7 Qxe6 2.Rxh7 Qe3 3.Bc5 Ne7 4.Bxe3 Rc7 5.Qxh5+ Kd8 6.Rd2+ Rd7 7.Bb6+ Kc8 8.Qe8+ Kb7 9.Rxd7+ Kxb6 10.Rdxe7 Ka5 11.Qd8+ Ka4 12.Rh4+ b4 13.cxb4 Kb5 14.Qd7+ Kb6 15.Re6#
+- (#15) Depth: 13 00:00:08 6861kN
1.Rxg7 Qxe6 2.Rxh7 Nd8 3.Qxh5+ Nf7 4.Rxf7 Qxf7 5.Re2+ Kd7 6.Qxf7+ Kc6 7.Qxf5 Kb7 8.Qd7+ Kb6 9.Qxc8 b4 10.Bxb4 Kb5 11.Qd7+ Kb6 12.Re6#
+- (#12) Depth: 14 00:00:15 11170kN
1.Rxg7 Qxe6 2.Rxh7 Nd8 3.Re2 Rxc3 4.Rxe6+ Nxe6 5.Ba3 Rc1+ 6.Qxc1 Kd8 7.Qd2+ Kc8 8.Qd7+ Kb8 9.Qb7#
+- (#9) Depth: 15 00:01:19 43265kN

[Dann Corbit]

There is a big difference between a mate prover and a chess playing program.

When Chest announces the mate result, we know for sure that it is a checkmate in N (like a chess program) and also that there are no mates in N-m.

This is an example where Chest takes a long time and chess playing programs are fast. There are also examples where chest is ten to 100 times faster than a chess playing program. So it goes both ways.

[Dann Corbit]

Are they all mate problems?

--Jon

Yes, all of them are supposed to be mate problems. They are from the Chest mate database, the Problemist mate databases, and many other sources.

Because they are often written by composers, there are some oddball positions in there and also some very clever ones which are very pretty to look at.