Mate in 8 - hard for some easy for others

Discussion of anything and everything relating to chess playing software and machines.

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kiroje
Posts: 76
Joined: Wed Jul 25, 2012 10:12 am
Location: Copenhagen, Denmark
Full name: Kim Jensen

Mate in 8 - hard for some easy for others

Post by kiroje »

Having fun with endgame composition and mate studies I composed some problems that I of course verify with computers.

Here is one that is a offspring from another composition I made that seems to be hard for some and easy for others.

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Stockfish 18 - 1 thread 8GB hash

Code: Select all

6:55/157-16: 1.Ne6, 507,6M nodes (1,2M nps), 8GB hash
0:00: +2.37/1 1.Ne6
0:00: +3.25/2 1.Ne6
0:00: +3.14/3 1.Ne6 c5 2.c3
0:00: +3.34/4 1.Ne6 c5 2.c3 c4
0:00: +3.27/5 1.Ne6 c5 2.Kb5 c4 3.c3
0:00: +3.01/6 1.Ne6 c5 2.Kb5 c4 3.Ka4 c3
0:00: +2.81/7 1.Ne6 c5 2.Kb5 c4 3.Kb4
0:00: +3.41/8 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8
0:00: +3.43/9 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7
0:00: +3.64/10 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8
0:00: +3.48/11 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7
0:00: +3.95/12 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6
0:00: +4.23/13 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6 Rg8 10.Nd5+ Ke6
0:00: +4.51/14 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6 Kf6 10.Nd4 Rg8 11.Nd5+ Ke5
0:00: +4.70/15 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.a7 Rc8 9.Nxc3 Kf6 10.Kb7 Rh8 11.N3d5+ Ke5 12.Nb6 Kd4
0:00: +5.15/16 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rg8
0:00: +5.91/17 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.a7 Rf8
0:02: +6.67/18 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rb2 9.a7 Kf8
0:04: +7.74/19 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Kf6 9.a7 Rc8 10.Kb7 Rg8 11.N3b5 Rg5
0:09: +8.23/20 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg6
0:15: +9.06/21 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg8
0:46: +11.36/22 1.Ne6
0:57: +11.36/22 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg7 11.Kb7
1:11: +14.41/23 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg7 11.Kb7 Kh7
1:30: +19.46/24 1.Ne6
1:51: +26.41/24 1.Ne6
1:55: +17.14/24 1.Ne6 c5
1:55: +17.14/24 1.Ne6
2:09: +34.61/24 1.Ne6
2:26: +56.59/24 1.Ne6
2:26: +27.29/24 1.Ne6 c5
2:26: +27.29/24 1.Ne6
2:38: +68.43/24 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf8 10.a7 Kg7 11.Kb7 Rh8 12.c4 Kf7 13.c5
6:21: #26/25 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf6 12.Qa6+ Kg5 13.Qxg6+ Kxg6 14.N3b5 Kh6 15.c4 Kg6 16.c5 Kg5 17.c6 Kf5 18.Nd6+ Kg6 19.Nd5 Kg5 20.c7 Kg4 21.c8=Q+ Kg3 22.Qc3+ Kf2 23.Ne4+ Kf1 24.Qf3+ Ke1 25.Qf2+ Kd1 26.Qd2#
6:21: +19.46/26 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.N3d5+ Kf7 11.a8=Q Rxa8 12.Nxa8 Ke6 13.Ndc7+ Ke7
6:21: #27/27 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #27/28 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #27/29 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #26/30 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #26/31 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #26/32 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #21/33 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke8 10.Nb5 Ke7 11.Kb6 Kf6 12.Nac7 Kf5 13.a7 Kf4 14.c4 Ke4 15.a8=Q+ Ke5 16.c5 Kf6 17.Qf3+ Kg5 18.Ne6+ Kg6 19.Qf4 Kh7 20.Qg5 Kh8 21.Qg7#
6:21: #21/34 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke7 10.Nb5 Kf6 11.Nac7 Kg6 12.a7 Kh5 13.c4 Kg6 14.Kb6 Kf5 15.a8=Q Ke5 16.Ne6 Kxe6 17.Qf3 Ke5 18.Kc6 Ke6 19.Qf4 Ke7 20.Nc7 Kd8 21.Qf8#
6:21: #21/35 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke7 10.Nb5 Kf6 11.Nac7 Kg6 12.a7 Kg5 13.Kb6 Kg6 14.a8=Q Kf5 15.Qf3+ Kg5 16.Kb7 Kh6 17.Qf6+ Kh5 18.Qf4 Kg6 19.Ne6 Kh7 20.Qf6 Kg8 21.Qg7#
6:21: #8/36 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Nxa7#
Jackal v2.0.0

Code: Select all

0:04/11-29: 1.Ne6, 3,3M nodes (764,2K nps), 8GB hash
0:00: +1.87/4 1.Ne6 c5 2.Nb7 Kc8 3.Kb5 Kd7 4.Nexc5+
0:00: +1.83/5 1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nc4 Kc8 5.Nd4
0:00: +2.13/6 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.c3
0:00: +2.23/7 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nd6 Kxa8 8.c4 Kb8 9.Ne8
0:00: +2.45/8 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nd6 Kxa8 8.c3 Kb8 9.Nf5
0:00: +2.67/9 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Ne8 Kd8 9.Ncd6 Ke7 10.c4 Kf8
0:00: +2.85/10 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb6+ Kd8 9.c4 Ke7
0:00: +3.21/11 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb6+ Kd8 9.Nbd5 Kc8 10.c3 Kd8
0:00: +3.59/12 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.c3 Kb8 9.Ne5 Kc8 10.Nd5
0:00: +3.62/13 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.c3 Kb8 9.Ne5 Kc8 10.Ng6 Kb8 11.c4
0:00: +3.47/14 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb5 Kb8 9.Kd5 Ka8 10.Kd4 Kb8 11.Nca3 Kc8
0:00: +3.03/15 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Kb8 6.Nxc3 Kc8 7.Nxa8 Kb8 8.Nc7 Kc8 9.Ne6 Kb8 10.Na2 Ka8 11.c4 Kb8 12.Kd7 Ka8 13.c5 Kb8
0:01: #8/10 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Ned4 Kc8 7.Nc6 Rb8 8.Nfe7#
“Modern chess is too much concerned with things like pawn structure. Forget it, checkmate ends the game.” – Nigel Short
peter
Posts: 3591
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Mate in 8 - hard for some easy for others

Post by peter »

kiroje wrote: Mon May 18, 2026 2:06 pm Here is one that is a offspring from another composition I made that seems to be hard for some and easy for others.

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Code: Select all

rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - -

Engine: Raphael4.1 (1024 MB)
von Rei Meguro

27/45  0:01   +4.82    1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Sec7 Tb8 6.Sxa7+ Kd8 7.Sab5 Ke7 
                       8.a7 Th8 9.Sxc3 Kf6 10.S3d5+ Ke5 
                       11.c4 Kd4 12.Kb5 Tc8 13.c5 Kd3 
                       14.Kb6 (1.936.827) 1270 

...

29/249 0:03   +5.03    1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Sec7 Tb8 6.Sxa7+ Kd8 7.Sab5 Ke7 
                       8.a7 Td8 9.Sxc3 Kf6 10.S3d5+ Kf5 
                       11.c4 Kg4 12.c5 Kh4 13.Kb7 Kg3 
                       14.Sf6 (4.780.278) 1286 

30/249 0:05   +M8      1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Kd6 Kb8 6.Sd8 Kc8 7.Sc6 Tb8 
                       8.Sbxa7+ (7.046.890) 1230 

...

53/249 0:13   +M8      1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Kd6 Kb8 6.Sd8 Kc8 7.Sc6 Tb8 
                       8.Sbxa7+ (20.814.291) 1585
Also single thread (4.3GHz), regards
Peter.
kiroje
Posts: 76
Joined: Wed Jul 25, 2012 10:12 am
Location: Copenhagen, Denmark
Full name: Kim Jensen

Re: Mate in 8 - hard for some easy for others

Post by kiroje »

peter wrote: Mon May 18, 2026 2:23 pm
kiroje wrote: Mon May 18, 2026 2:06 pm Here is one that is a offspring from another composition I made that seems to be hard for some and easy for others.

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Code: Select all

rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - -

Engine: Raphael4.1 (1024 MB)
von Rei Meguro

27/45  0:01   +4.82    1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Sec7 Tb8 6.Sxa7+ Kd8 7.Sab5 Ke7 
                       8.a7 Th8 9.Sxc3 Kf6 10.S3d5+ Ke5 
                       11.c4 Kd4 12.Kb5 Tc8 13.c5 Kd3 
                       14.Kb6 (1.936.827) 1270 

...

29/249 0:03   +5.03    1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Sec7 Tb8 6.Sxa7+ Kd8 7.Sab5 Ke7 
                       8.a7 Td8 9.Sxc3 Kf6 10.S3d5+ Kf5 
                       11.c4 Kg4 12.c5 Kh4 13.Kb7 Kg3 
                       14.Sf6 (4.780.278) 1286 

30/249 0:05   +M8      1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Kd6 Kb8 6.Sd8 Kc8 7.Sc6 Tb8 
                       8.Sbxa7+ (7.046.890) 1230 

...

53/249 0:13   +M8      1.Se6 c5 2.Kb5 c4 3.Kc6 c3 4.Sb5 Kc8 
                       5.Kd6 Kb8 6.Sd8 Kc8 7.Sc6 Tb8 
                       8.Sbxa7+ (20.814.291) 1585
Also single thread (4.3GHz), regards
Pretty impressive speed for solving :)
“Modern chess is too much concerned with things like pawn structure. Forget it, checkmate ends the game.” – Nigel Short
User avatar
Steve Maughan
Posts: 1328
Joined: Wed Mar 08, 2006 8:28 pm
Location: Florida, USA

Re: Mate in 8 - hard for some easy for others

Post by Steve Maughan »

The latest version of Juggernaut solve to +M8 in 40 secs on a modern AMD laptop

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - -

Code: Select all

Engine: Juggernaut Latest (1024 MB)
by Steve Maughan

23/47  0:03   +23.14   1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 
                       5.Nc7 Kc8 6.Nxa8 Kd8 7.Kb7 Kd7 
                       8.Kxa7 Kc6 9.Nab6 Kc7 10.c3 Kd8 
                       11.Kb7 Ke7 12.a7 Kf6 13.a8Q Kf5 
                       14.Nd6+ (24.075.212) 6732 

24/48  0:38   +M18     1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 
                       5.Nc7 Kc8 6.Nxa8 Kd8 7.Kb7 Kd7 
                       8.Kxa7 Kc6 9.Nab6 Kc7 10.c3 Kd8 
                       11.Kb7 Ke7 12.a7 Kf6 13.a8Q Kf5 
                       14.Nd5 (203.904.180) 5336 

27/48  0:40   +M8      1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 
                       5.Kd6 Kb8 6.Nd8 Kc8 7.Nc6 Rb8 
                       8.Nfe7+ (215.976.171) 5372 
http://www.chessprogramming.net - Juggernaut & Maverick Chess Engine
kiroje
Posts: 76
Joined: Wed Jul 25, 2012 10:12 am
Location: Copenhagen, Denmark
Full name: Kim Jensen

Re: Mate in 8 - hard for some easy for others

Post by kiroje »

Steve Maughan wrote: Mon May 18, 2026 3:14 pm The latest version of Juggernaut solve to +M8 in 40 secs on a modern AMD laptop

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - -

Code: Select all

Engine: Juggernaut Latest (1024 MB)
by Steve Maughan

23/47  0:03   +23.14   1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 
                       5.Nc7 Kc8 6.Nxa8 Kd8 7.Kb7 Kd7 
                       8.Kxa7 Kc6 9.Nab6 Kc7 10.c3 Kd8 
                       11.Kb7 Ke7 12.a7 Kf6 13.a8Q Kf5 
                       14.Nd6+ (24.075.212) 6732 

24/48  0:38   +M18     1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 
                       5.Nc7 Kc8 6.Nxa8 Kd8 7.Kb7 Kd7 
                       8.Kxa7 Kc6 9.Nab6 Kc7 10.c3 Kd8 
                       11.Kb7 Ke7 12.a7 Kf6 13.a8Q Kf5 
                       14.Nd5 (203.904.180) 5336 

27/48  0:40   +M8      1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 
                       5.Kd6 Kb8 6.Nd8 Kc8 7.Nc6 Rb8 
                       8.Nfe7+ (215.976.171) 5372 
Again very impressive, makes my small toy engine look a bit stupid :D
“Modern chess is too much concerned with things like pawn structure. Forget it, checkmate ends the game.” – Nigel Short
Jouni
Posts: 3897
Joined: Wed Mar 08, 2006 8:15 pm
Full name: Jouni Uski

Re: Mate in 8 - hard for some easy for others

Post by Jouni »

511 ms for Stockfish dev:

info depth 40 seldepth 26 multipv 1 score mate 8 nodes 652612 nps 1277127 hashfull 1 tbhits 0 time 511 pv c5e6 c6c5 a5b5 c5c4 b5c5 c4c3 d6b5 b8c8 c5d6 c8b8 b5d4 b8c8 d4c6 a8b8 c6a7
Jouni
User avatar
Master Om
Posts: 456
Joined: Wed Nov 24, 2010 10:57 am
Location: INDIA

Re: Mate in 8 - hard for some easy for others

Post by Master Om »

kiroje wrote: Mon May 18, 2026 2:06 pm Having fun with endgame composition and mate studies I composed some problems that I of course verify with computers.

Here is one that is a offspring from another composition I made that seems to be hard for some and easy for others.

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Stockfish 18 - 1 thread 8GB hash

Code: Select all

6:55/157-16: 1.Ne6, 507,6M nodes (1,2M nps), 8GB hash
0:00: +2.37/1 1.Ne6
0:00: +3.25/2 1.Ne6
0:00: +3.14/3 1.Ne6 c5 2.c3
0:00: +3.34/4 1.Ne6 c5 2.c3 c4
0:00: +3.27/5 1.Ne6 c5 2.Kb5 c4 3.c3
0:00: +3.01/6 1.Ne6 c5 2.Kb5 c4 3.Ka4 c3
0:00: +2.81/7 1.Ne6 c5 2.Kb5 c4 3.Kb4
0:00: +3.41/8 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8
0:00: +3.43/9 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7
0:00: +3.64/10 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8
0:00: +3.48/11 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7
0:00: +3.95/12 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6
0:00: +4.23/13 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6 Rg8 10.Nd5+ Ke6
0:00: +4.51/14 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6 Kf6 10.Nd4 Rg8 11.Nd5+ Ke5
0:00: +4.70/15 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.a7 Rc8 9.Nxc3 Kf6 10.Kb7 Rh8 11.N3d5+ Ke5 12.Nb6 Kd4
0:00: +5.15/16 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rg8
0:00: +5.91/17 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.a7 Rf8
0:02: +6.67/18 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rb2 9.a7 Kf8
0:04: +7.74/19 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Kf6 9.a7 Rc8 10.Kb7 Rg8 11.N3b5 Rg5
0:09: +8.23/20 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg6
0:15: +9.06/21 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg8
0:46: +11.36/22 1.Ne6
0:57: +11.36/22 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg7 11.Kb7
1:11: +14.41/23 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg7 11.Kb7 Kh7
1:30: +19.46/24 1.Ne6
1:51: +26.41/24 1.Ne6
1:55: +17.14/24 1.Ne6 c5
1:55: +17.14/24 1.Ne6
2:09: +34.61/24 1.Ne6
2:26: +56.59/24 1.Ne6
2:26: +27.29/24 1.Ne6 c5
2:26: +27.29/24 1.Ne6
2:38: +68.43/24 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf8 10.a7 Kg7 11.Kb7 Rh8 12.c4 Kf7 13.c5
6:21: #26/25 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf6 12.Qa6+ Kg5 13.Qxg6+ Kxg6 14.N3b5 Kh6 15.c4 Kg6 16.c5 Kg5 17.c6 Kf5 18.Nd6+ Kg6 19.Nd5 Kg5 20.c7 Kg4 21.c8=Q+ Kg3 22.Qc3+ Kf2 23.Ne4+ Kf1 24.Qf3+ Ke1 25.Qf2+ Kd1 26.Qd2#
6:21: +19.46/26 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.N3d5+ Kf7 11.a8=Q Rxa8 12.Nxa8 Ke6 13.Ndc7+ Ke7
6:21: #27/27 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #27/28 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #27/29 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #26/30 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #26/31 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #26/32 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #21/33 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke8 10.Nb5 Ke7 11.Kb6 Kf6 12.Nac7 Kf5 13.a7 Kf4 14.c4 Ke4 15.a8=Q+ Ke5 16.c5 Kf6 17.Qf3+ Kg5 18.Ne6+ Kg6 19.Qf4 Kh7 20.Qg5 Kh8 21.Qg7#
6:21: #21/34 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke7 10.Nb5 Kf6 11.Nac7 Kg6 12.a7 Kh5 13.c4 Kg6 14.Kb6 Kf5 15.a8=Q Ke5 16.Ne6 Kxe6 17.Qf3 Ke5 18.Kc6 Ke6 19.Qf4 Ke7 20.Nc7 Kd8 21.Qf8#
6:21: #21/35 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke7 10.Nb5 Kf6 11.Nac7 Kg6 12.a7 Kg5 13.Kb6 Kg6 14.a8=Q Kf5 15.Qf3+ Kg5 16.Kb7 Kh6 17.Qf6+ Kh5 18.Qf4 Kg6 19.Ne6 Kh7 20.Qf6 Kg8 21.Qg7#
6:21: #8/36 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Nxa7#
Jackal v2.0.0

Code: Select all

0:04/11-29: 1.Ne6, 3,3M nodes (764,2K nps), 8GB hash
0:00: +1.87/4 1.Ne6 c5 2.Nb7 Kc8 3.Kb5 Kd7 4.Nexc5+
0:00: +1.83/5 1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nc4 Kc8 5.Nd4
0:00: +2.13/6 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.c3
0:00: +2.23/7 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nd6 Kxa8 8.c4 Kb8 9.Ne8
0:00: +2.45/8 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nd6 Kxa8 8.c3 Kb8 9.Nf5
0:00: +2.67/9 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Ne8 Kd8 9.Ncd6 Ke7 10.c4 Kf8
0:00: +2.85/10 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb6+ Kd8 9.c4 Ke7
0:00: +3.21/11 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb6+ Kd8 9.Nbd5 Kc8 10.c3 Kd8
0:00: +3.59/12 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.c3 Kb8 9.Ne5 Kc8 10.Nd5
0:00: +3.62/13 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.c3 Kb8 9.Ne5 Kc8 10.Ng6 Kb8 11.c4
0:00: +3.47/14 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb5 Kb8 9.Kd5 Ka8 10.Kd4 Kb8 11.Nca3 Kc8
0:00: +3.03/15 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Kb8 6.Nxc3 Kc8 7.Nxa8 Kb8 8.Nc7 Kc8 9.Ne6 Kb8 10.Na2 Ka8 11.c4 Kb8 12.Kd7 Ka8 13.c5 Kb8
0:01: #8/10 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Ned4 Kc8 7.Nc6 Rb8 8.Nfe7#
Reckless 0.10

Code: Select all

 [Mate in 8]  d=187  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:50) 494949kN
 [Mate in 8]  d=186  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:49) 483003kN
 [Mate in 8]  d=185  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:47) 466211kN
 [Mate in 8]  d=184  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:44) 436552kN
 [Mate in 8]  d=183  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:44) 432853kN
 [Mate in 8]  d=182  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:43) 430477kN
 [Mate in 8]  d=181  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:43) 430048kN
 [Mate in 8]  d=180  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:41) 414913kN
 [Mate in 8]  d=179  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:41) 414678kN
 [Mate in 8]  d=178  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:28) 287949kN
 [Mate in 8]  d=177  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:27) 287767kN
 [Mate in 8]  d=176  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:27) 287547kN
 [Mate in 8]  d=175  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:27) 287513kN
 [Mate in 8]  d=174  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:27) 285396kN
 [Mate in 8]  d=173  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:27) 285395kN
 [Mate in 8]  d=172  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:27) 285394kN
 [Mate in 8]  d=171  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:17) 194483kN
 [Mate in 8]  d=170  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:17) 194368kN
 [Mate in 8]  d=169  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:17) 194141kN
 [Mate in 8]  d=168  1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Nfd4 Kc8 7.Nc6 Rb8 8.Nxa7#(0:00:14) 166380kN
Always Expect the Unexpected
User avatar
Master Om
Posts: 456
Joined: Wed Nov 24, 2010 10:57 am
Location: INDIA

Re: Mate in 8 - hard for some easy for others

Post by Master Om »

kiroje wrote: Mon May 18, 2026 2:06 pm Having fun with endgame composition and mate studies I composed some problems that I of course verify with computers.

Here is one that is a offspring from another composition I made that seems to be hard for some and easy for others.

[d]rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Stockfish 18 - 1 thread 8GB hash

Code: Select all

6:55/157-16: 1.Ne6, 507,6M nodes (1,2M nps), 8GB hash
0:00: +2.37/1 1.Ne6
0:00: +3.25/2 1.Ne6
0:00: +3.14/3 1.Ne6 c5 2.c3
0:00: +3.34/4 1.Ne6 c5 2.c3 c4
0:00: +3.27/5 1.Ne6 c5 2.Kb5 c4 3.c3
0:00: +3.01/6 1.Ne6 c5 2.Kb5 c4 3.Ka4 c3
0:00: +2.81/7 1.Ne6 c5 2.Kb5 c4 3.Kb4
0:00: +3.41/8 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8
0:00: +3.43/9 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7
0:00: +3.64/10 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8
0:00: +3.48/11 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7
0:00: +3.95/12 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6
0:00: +4.23/13 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6 Rg8 10.Nd5+ Ke6
0:00: +4.51/14 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Rc8 8.a7 Ke7 9.Kb6 Kf6 10.Nd4 Rg8 11.Nd5+ Ke5
0:00: +4.70/15 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.a7 Rc8 9.Nxc3 Kf6 10.Kb7 Rh8 11.N3d5+ Ke5 12.Nb6 Kd4
0:00: +5.15/16 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rg8
0:00: +5.91/17 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.a7 Rf8
0:02: +6.67/18 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rb2 9.a7 Kf8
0:04: +7.74/19 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Kf6 9.a7 Rc8 10.Kb7 Rg8 11.N3b5 Rg5
0:09: +8.23/20 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg6
0:15: +9.06/21 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg8
0:46: +11.36/22 1.Ne6
0:57: +11.36/22 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg7 11.Kb7
1:11: +14.41/23 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf7 10.a7 Kg7 11.Kb7 Kh7
1:30: +19.46/24 1.Ne6
1:51: +26.41/24 1.Ne6
1:55: +17.14/24 1.Ne6 c5
1:55: +17.14/24 1.Ne6
2:09: +34.61/24 1.Ne6
2:26: +56.59/24 1.Ne6
2:26: +27.29/24 1.Ne6 c5
2:26: +27.29/24 1.Ne6
2:38: +68.43/24 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.Nd5+ Kf8 10.a7 Kg7 11.Kb7 Rh8 12.c4 Kf7 13.c5
6:21: #26/25 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf6 12.Qa6+ Kg5 13.Qxg6+ Kxg6 14.N3b5 Kh6 15.c4 Kg6 16.c5 Kg5 17.c6 Kf5 18.Nd6+ Kg6 19.Nd5 Kg5 20.c7 Kg4 21.c8=Q+ Kg3 22.Qc3+ Kf2 23.Ne4+ Kf1 24.Qf3+ Ke1 25.Qf2+ Kd1 26.Qd2#
6:21: +19.46/26 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.N3d5+ Kf7 11.a8=Q Rxa8 12.Nxa8 Ke6 13.Ndc7+ Ke7
6:21: #27/27 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #27/28 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #27/29 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qe6+ Kg5 14.Qxg6+ Kxg6 15.N3b5 Kg5 16.c4 Kh5 17.c5 Kg5 18.Ne8 Kh4 19.c6 Kh3 20.c7 Kh4 21.Ned6 Kh5 22.c8=Q Kg5 23.Qf5+ Kh4 24.Nc7 Kg3 25.Ne4+ Kg2 26.Qf2+ Kh1 27.Ng3#
6:21: #26/30 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #26/31 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #26/32 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Rb8 6.Nxa7+ Kd8 7.Nab5 Ke7 8.Nxc3 Rc8 9.a7 Rg8 10.a8=Q Rg6+ 11.Kb7 Kf7 12.Qe8+ Kf6 13.Qxg6+ Kxg6 14.N3b5 Kg5 15.c4 Kh5 16.c5 Kg5 17.Ne8 Kh4 18.c6 Kh3 19.c7 Kh4 20.Ned6 Kh5 21.c8=Q Kg5 22.Qf5+ Kh4 23.Nc7 Kg3 24.Ne4+ Kg2 25.Qf2+ Kh1 26.Ng3#
6:21: #21/33 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke8 10.Nb5 Ke7 11.Kb6 Kf6 12.Nac7 Kf5 13.a7 Kf4 14.c4 Ke4 15.a8=Q+ Ke5 16.c5 Kf6 17.Qf3+ Kg5 18.Ne6+ Kg6 19.Qf4 Kh7 20.Qg5 Kh8 21.Qg7#
6:21: #21/34 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke7 10.Nb5 Kf6 11.Nac7 Kg6 12.a7 Kh5 13.c4 Kg6 14.Kb6 Kf5 15.a8=Q Ke5 16.Ne6 Kxe6 17.Qf3 Ke5 18.Kc6 Ke6 19.Qf4 Ke7 20.Nc7 Kd8 21.Qf8#
6:21: #21/35 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kd8 7.Ncb6 Ke7 8.Nc8+ Kd8 9.Nxa7 Ke7 10.Nb5 Kf6 11.Nac7 Kg6 12.a7 Kg5 13.Kb6 Kg6 14.a8=Q Kf5 15.Qf3+ Kg5 16.Kb7 Kh6 17.Qf6+ Kh5 18.Qf4 Kg6 19.Ne6 Kh7 20.Qf6 Kg8 21.Qg7#
6:21: #8/36 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Nxa7#
Jackal v2.0.0

Code: Select all

0:04/11-29: 1.Ne6, 3,3M nodes (764,2K nps), 8GB hash
0:00: +1.87/4 1.Ne6 c5 2.Nb7 Kc8 3.Kb5 Kd7 4.Nexc5+
0:00: +1.83/5 1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nc4 Kc8 5.Nd4
0:00: +2.13/6 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.c3
0:00: +2.23/7 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nd6 Kxa8 8.c4 Kb8 9.Ne8
0:00: +2.45/8 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nd6 Kxa8 8.c3 Kb8 9.Nf5
0:00: +2.67/9 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Ne8 Kd8 9.Ncd6 Ke7 10.c4 Kf8
0:00: +2.85/10 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb6+ Kd8 9.c4 Ke7
0:00: +3.21/11 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb6+ Kd8 9.Nbd5 Kc8 10.c3 Kd8
0:00: +3.59/12 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.c3 Kb8 9.Ne5 Kc8 10.Nd5
0:00: +3.62/13 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.c3 Kb8 9.Ne5 Kc8 10.Ng6 Kb8 11.c4
0:00: +3.47/14 1.Ne6 c5 2.Kb5 c4 3.Nxc4 Kc8 4.Kc6 Kb8 5.Nc7 Kc8 6.Nxa8 Kb8 7.Nc7 Kc8 8.Nb5 Kb8 9.Kd5 Ka8 10.Kd4 Kb8 11.Nca3 Kc8
0:00: +3.03/15 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nb5 Kc8 5.Nec7 Kb8 6.Nxc3 Kc8 7.Nxa8 Kb8 8.Nc7 Kc8 9.Ne6 Kb8 10.Na2 Ka8 11.c4 Kb8 12.Kd7 Ka8 13.c5 Kb8
0:01: #8/10 1.Ne6 c5 2.Kb5 c4 3.Kc6 c3 4.Nf5 Kc8 5.Kd6 Kb8 6.Ned4 Kc8 7.Nc6 Rb8 8.Nfe7#
Crystal 5 KWK

Code: Select all

 [Mate in 8]  d=54  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:10) 333450kN
 [Mate in 8]  d=53  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:10) 313258kN
 [Mate in 8]  d=52  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:09) 292467kN
 [Mate in 8]  d=51  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:08) 271368kN
 [Mate in 8]  d=50  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:08) 252431kN
 [Mate in 8]  d=49  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:07) 234281kN
 [Mate in 8]  d=48  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:07) 217975kN
 [Mate in 8]  d=47  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:06) 203768kN
 [Mate in 8]  d=46  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:06) 188180kN
 [Mate in 8]  d=45  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:05) 174778kN
 [Mate in 8]  d=44  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:05) 161460kN
 [Mate in 8]  d=43  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:04) 148936kN
 [Mate in 8]  d=42  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:04) 136963kN
 [Mate in 8]  d=41  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:04) 127533kN
 [Mate in 8]  d=40  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:03) 118666kN
 [Mate in 8]  d=39  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:03) 107093kN
 [Mate in 8]  d=38  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:03) 98382kN
 [Mate in 8]  d=37  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:02) 90228kN
 [Mate in 8]  d=36  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:02) 82888kN
 [Mate in 8]  d=35  1.Ne6 c5 2.Kb5 c4 3.Kc5 c3 4.Nb5 Kc8 5.Kd6 Kb8 6.Nbd4 Kc8 7.Nc6 Rb8 8.Ne7#(0:00:02) 76833kN
Always Expect the Unexpected
User avatar
Ajedrecista
Posts: 2242
Joined: Wed Jul 13, 2011 9:04 pm
Location: Madrid, Spain.

Re: Mate in 8 - hard for some, easy for others.

Post by Ajedrecista »

Hello Kim:

Thanks for your problem. Let us start with the famous Chest 5.2 checkmate solver:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

ChestUCI:
FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - -   (5+4)
Stellungs-Analyse:  C0/R0/K2/P1/X1   W:4/19
Suche nach Matt in 10 ...  (Hash=64MB)
   8	00:02	     681.767	682.449	+M8	Nc5e6
Suche abgeschlossen ...  (Zeit=1.45s)
Matt in 8 gefunden !  (1 Lösung in 00:01)
  8/8	00:02	   1.005.187	691.801	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Nd6f5 c4c3 Kb5c5 Kb8c8 Kc5d6 Kc8b8 Nf5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
We can continue with JetChess 1.0.0.0. It is a perft counter, but can solve some checkmates:

Code: Select all

rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

  1  Nc5-b7   0
  2  Nc5-d7   0
  3  Nc5-e6   Mate
  4  Nc5-a4   0
  5  Nc5-b3   0
  6  Nc5-d3   0
  7  Nc5-e4   0
  8  Nd6-b7   0
  9  Nd6-c8   0
 10  Nd6-e8   0
 11  Nd6-f7   0
 12  Nd6-b5   0
 13  Nd6-c4   0
 14  Nd6-e4   0
 15  Nd6-f5   0
 16   c2-c3   0
 17   c2-c4   0
 18  Ka5-a4   0
 19  Ka5-b4   0

Solution:  Nc5-e6  (mate in 8)

Time: 604 ms
------------

Huntsman is considered a good checkmate finder:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Huntsman:
Found 145 tablebases
classical evaluation enabled
[...]
 48/48	00:06	  13.346.833	2.126.985	+152,57	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6e5 c2c3 Ke5d5 c3c4+ Kd5c5 Ka7b8 Kc5d4 a6a7 Kd4c3 a7a8Q Kc3d4 c4c5 Kd4xc5
 49/52	00:08	  18.685.173	2.352.111	+M22	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c6 Nf8e6 Kc6b5 c2c3 Kb5c4 Ka7b6 Kc4d5 a6a7 Kd5xe6 c3c4 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 50/42	00:08	  20.363.432	2.340.893	+M21	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c7 c2c4 Kc7c6 Nf8e6 Kc6d7 Ka7b6 Kd7xe6 a6a7 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 51/42	00:08	  20.367.037	2.341.038	+M21	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c7 c2c4 Kc7c6 Nf8e6 Kc6d7 Ka7b6 Kd7xe6 a6a7 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 52/42	00:09	  21.590.646	2.388.081	+M21	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c7 c2c4 Kc7c6 Nf8e6 Kc6d7 Ka7b6 Kd7xe6 a6a7 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 53/42	00:09	  21.811.843	2.389.553	+M21	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c7 c2c4 Kc7c6 Nf8e6 Kc6d7 Ka7b6 Kd7xe6 a6a7 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 54/42	00:09	  23.151.309	2.414.109	+M21	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c7 c2c4 Kc7c6 Nf8e6 Kc6d7 Ka7b6 Kd7xe6 a6a7 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 55/42	00:10	  24.102.833	2.448.479	+M21	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6f8 Kb8c8 Nc4d6+ Kc8d8 Kc6b7 Kd8e7 Kb7xa8 Ke7xd6 Ka8xa7 Kd6c7 c2c4 Kc7c6 Nf8e6 Kc6d7 Ka7b6 Kd7xe6 a6a7 Ke6f6 c4c5 Kf6e7 a7a8Q Ke7e6 c5c6 Ke6e5 c6c7 Ke5f4 c7c8Q Kf4e3 Qc8c3+ Ke3f2 Qc3f3+ Kf2e1 Qa8a5+
 56/42	00:11	  27.811.956	2.534.349	+M9	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Kc6d6 Kb8c8 Kd6e7 Kc8b8 Nc4a5 Kb8c8 Na5c6 Ra8b8 Nc6xa7+
 57/18	00:11	  27.839.276	2.531.073	+M9	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Kc6d6 Kb8c8 Kd6e7 Kc8b8 Nc4a5 Kb8c8 Na5c6 Ra8b8 Nc6xa7+
[...]
 73/18	00:16	  32.763.221	2.046.933	+M9	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Kc6d6 Kb8c8 Kd6e7 Kc8b8 Nc4a5 Kb8c8 Na5c6 Ra8b8 Nc6xa7+
 74/18	00:16	  33.757.817	2.017.198	+M9	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Kc6d6 Kb8c8 Kd6e7 Kc8b8 Nc4a5 Kb8c8 Na5c6 Ra8b8 Nc6xa7+
 75/16	00:17	  34.147.846	2.003.511	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
 76/16	00:18	  35.202.700	1.960.607	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
[...]
 84/16	00:20	  40.948.009	1.992.312	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
 85/16	00:21	  42.477.107	2.014.851	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
------------

We can finish with some old rockers. From newest to oldest:

Hermann 2.4 64-bit from 2008/11/12 simply shined:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Hermann 2.4 64 bit:
  1/5	00:00	          27	27.000	+1,88	Nc5e6
 12/25	00:00	     941.765	1.543.877	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+
 13/27	00:01	   1.642.893	1.522.607	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+

ProDeo 1.5 from 2007/06/06 found a checkmate in 10 moves almost immediately and apparently stalled:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

ProDeo 1.5:
   1	00:00	           5	5.000	+1,78	Ka5b4
   2	00:00	          76	76.000	+1,49	Ka5b4 Kb8c7
   2	00:00	         108	108.000	+1,49	Nc5e6
[...]
  14	00:00	     777.913	777.913.000	+5,72	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6e4 Kb8c8 Ne4c5 Ra8b8 Nc5b7 Rb8a8 Ne6c7 Kc8b8 Nb7c5 Kb8c8 Nc7xa8 Kc8d8
  15	00:00	   1.768.069	1.768.069.000	+5,72	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Nf5e7+ Kc8b8 Kc6b5
  16	00:00	   3.287.452	-1.007.515.296	+M10	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Nf5e7+ Kc8b8 Ne7d5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nd5e7+
Please look at the 32-bit integer overflow in speed. It looks like the reported time would be 1 ms as in the rest of depths, but 3,287,452 / 0.001 = 3,287,452,000 > 2^31 - 1 = 2,147,483,647 and the wrong output is 3,287,452,000 - 2^32 = -1,007,515,296 < 0.


Spike 1.2 from 2006/05/24 was also quite fast:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Spike 1.2:
[...]
  23	00:02	   6.303.755	2.763.592	+21,67	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6c7 Kb8c8 Nc7xa8 Kc8d8 Na8c7 Kd8e7 Nc7b5 Ke7f7 Nb5xa7 Kf7f6 Na7b5 Kf6g5 a6a7 Kg5f6 a7a8Q Kf6g6 Nc4e5+ Kg6f6
  24+	00:02	   6.316.185	2.769.042	+22,01	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6c7 Kb8c8 Nc7xa8 Kc8d8 Na8c7 Kd8e7 Nc7b5 Ke7f7 Nb5xa7 Kf7f6 Na7b5 Kf6g5 a6a7 Kg5f6 a7a8Q Kf6g6 Qa8g8+
  24+	00:02	   6.316.185	2.769.042	+22,01	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6c7 Kb8c8 Nc7xa8 Kc8d8 Na8c7 Kd8e7 Nc7b5 Ke7f7 Nb5xa7 Kf7f6 Na7b5 Kf6g5 a6a7 Kg5f6 a7a8Q Kf6g6 Qa8g8+
  24	00:02	   7.083.420	2.713.954	+M13	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Nc4e5 Kb8c8 Ne5d7 Ra8b8 Nd7xb8 Kc8xb8 c2c4 Kb8c8 c4c5 Kc8b8 Kc6d7
  24	00:02	   7.083.420	2.713.954	+M13	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Nc4e5 Kb8c8 Ne5d7 Ra8b8 Nd7xb8 Kc8xb8 c2c4 Kb8c8 c4c5 Kc8b8 Kc6d7
  24	00:03	   8.128.850	2.766.797	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
  24	00:03	   8.797.073	2.787.412	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
  25	00:03	  10.090.842	2.832.119	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
  25	00:03	  11.030.968	2.846.701	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+
  26	00:04	  12.946.639	2.896.987	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Nb5d4 Kb8c8 Nd4c6 Ra8b8 Nc6xa7+

AnMon 5.60 from 2006/01/28 scored Ne6 as the best mover with evals > 4 after more than 2e+8 nodes searched. Once Ne6 is played without clearing hash, found the checkmate almost immediately:

Code: Select all

FEN: rk6/p7/P1pNN3/K7/8/8/2P5/8 b - - 1 1

AnMon 5.60:
[...]
  16	00:00	     373.080	0	-8,38	c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Ne6c7 Ra8b8 Nb5xa7+ Kc8d8 Kc6d6 Rb8b1 Na7c6+ Kd8c8 Nc6a5 Kc8b8 Kd6e7
  17	00:00	   1.191.347	0	-299,85	c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nf5e7+

SOS 5.1 for Arena from 2005/02/22 shined like Hermann:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

SOS 5.1 for Arena:
[...]
 19/31	00:00	     870.593	1.731.731	+13,40	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6c7 Kb8c8 Nc7xa8 Kc8b8 Na8c7 Kb8c8 Nc4d6+ Kc8b8 Nd6b5 Kb8c8 Nb5xa7+ Kc8b8 Na7b5
 19/34	00:00	   1.052.322	1.839.804	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6
 20/34	00:00	   1.271.567	1.839.804	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+
 21/34	00:00	   1.619.219	2.033.955	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+
 22/34	00:00	   2.107.215	2.206.684	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+
 23/34	00:01	   2.826.874	2.312.195	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+
 24/34	00:01	   3.789.893	2.484.159	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6b5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nb5xa7+

Dragon 4.6 from 2004/10/20 found the checkmate quickly:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Dragon 4.6:
ucinewgame
RAZ infos
Temps restant : 0 secondes Temps limite : 1000000 secondes Temps limite absolu : 1000000 secondes
  15-	00:01	   3.335.790	0	+9,03	Nc5e6 c6c5 Nd6b5 Kb8c8 Ka5a4 Ra8b8 Nb5xa7+ Kc8d7 Ne6xc5+ Kd7d6 Nc5e4+ Kd6d5 Ne4f6+ Kd5c4 Nf6d7 Rb8a8 Nd7b6+ Kc4c3 Nb6xa8 Kc3xc2 Na7c6
[...]
  17	00:07	  23.380.415	2.956.059	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Nd6f5 Kb8c8 Kb5c6 Kc8b8 Kc6d6 c4c3 Ne6d8 Kb8c8 Nd8c6 Ra8b8 Nf5e7+
Detection de MAT : 29985 MAT08
  17	00:12	  41.768.887	3.340.059	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Nd6f5 Kb8c8 Kb5c6 Kc8b8 Kc6d6 c4c3 Ne6d8 Kb8c8 Nd8c6 Ra8b8 Nf5e7+

Nejmet 3.07 from 2003/06/23 was also very fast:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Nejmet 3.07:
[...]
 20/40	00:03	   7.079.289	2.359.763	+9,36	Nc5e6
 20/40	00:04	  10.695.351	2.673.837	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Kc6d6 Kc8b8 Ne6d8 Kb8c8 Nd8c6 Ra8b8 Nf5e7+
 20/40	00:06	  14.573.563	2.428.927	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Kc6d6 Kc8b8 Ne6d8 Kb8c8 Nd8c6 Ra8b8 Nf5e7+

Ruffian 1.05 from 2003/03/19 was also fast finding the desired checkmate:

Code: Select all

FEN: rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Ruffian 1.0.5:
[...]
 22/38	00:03	  13.199.504	4.137.775	+18,57	Nc5e6 c6c5 Ka5b5 c5c4 Nd6xc4 Kb8c8 Kb5c6 Kc8b8 Ne6c7 Kb8c8 Nc7xa8 Kc8d8 Kc6d6 Kd8e8 Na8c7+ Ke8f8 Nc7b5 Kf8f7 Nb5xa7 Kf7f6 Na7c6 Kf6f5 a6a7 Kf5e4 a7a8Q
 23/42+	00:06	  26.534.749	4.139.586	+18,92	Nc5e6
 23/42	00:06	  26.899.027	4.138.311	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nf5e7+
 24/42	00:06	  27.620.096	4.147.161	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nf5e7+
[...]
 30/42	00:08	  34.934.723	4.234.511	+M8	Nc5e6 c6c5 Ka5b5 c5c4 Kb5c6 c4c3 Nd6f5 Kb8c8 Kc6d6 Kc8b8 Ne6d4 Kb8c8 Nd4c6 Ra8b8 Nf5e7+
------------

I guess that nobody asked for perft, right?

Code: Select all

gperft 1.1 perft counter

rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

perft( 1) = 19
perft( 2) = 31
perft( 3) = 514
perft( 4) = 3,501
perft( 5) = 56,369
perft( 6) = 602,264
perft( 7) = 9,293,297
perft( 8) = 125,250,833
perft( 9) = 1,904,981,705
perft(10) = 27,766,141,209
perft(11) = 416,889,181,945
perft(12) = 6,306,813,038,506
perft(13) = 94,262,446,058,802
With the solution Ne6 having the less leaf nodes in every depth > 3:

Code: Select all

gperft 1.1 perft counter

rk6/p7/P1pN4/K1N5/8/8/2P5/8 w - - 0 1

Depth is 13.

Nc8        1,433,914,071,132
Ne8          310,767,622,950
Ndb7       2,339,970,129,692
Nf7        5,320,591,418,773
Nb5          650,406,715,110
Nf5        8,808,695,625,321
Nc4        7,011,650,401,200
Nde4       7,556,874,189,883
Ncb7       2,406,557,165,027
Nd7+       4,247,680,438,428
Ne6          209,799,397,547
Na4        3,325,221,562,421
Nce4       7,693,224,938,056
Nb3        5,905,405,675,086
Nd3        9,418,275,046,412
c3         3,568,217,888,742
c4         2,629,410,766,765
Ka4        9,217,128,488,663
Kb4       12,208,654,517,594
TOTAL     94,262,446,058,802
Regards from Spain.

Ajedrecista.
Aleks Peshkov
Posts: 996
Joined: Sun Nov 19, 2006 9:16 pm
Location: Russia
Full name: Aleks Peshkov

Re: Mate in 8 - hard for some easy for others

Post by Aleks Peshkov »

Code: Select all

info depth 24 nodes 35942 time 11 nps 2489609 score cp 1103 pv c5e6 c6c5 a5b5 c5c4 d6c4 b8c8 b5c6 c8b8 c4e5 b8c8 e5d7 a8b8 d7b8 c8b8 c2c4 b8a8 c4c5 a8b8 e6c7 b8c8 c7d5 c8b8 d5b4 b8a8
info depth 24 nodes 1199321 time 510 nps 2331449 score mate 8 pv c5e6 c6c5 a5b5 c5c4 b5c6 c4c3 d6b5 b8c8 c6d6 c8b8 e6d8 b8c8 d8c6 a8b8 b5a7
petrel dev. Remarkable unexpected search explosion.