robertnurnberg
commented
5 months ago Thank you very much for your very detailed analysis. So this is for the puzzle
8/1rp3p1/1p4N1/1P1P4/P1K3P1/1pBP1B2/pPp5/1bk5 w - - bm #36;meaning that you managed to shorten that from 36 to 27. Very impressive.
I will update my PV file with your line, and then also port it to https://github.com/vondele/matetrack.
Yery
This is one has no PV yet: 8/1rp3p1/1p4N1/1P1P4/P1K3P1/1pBP1B2/pPp5/1bk5 w - - 0 1
I analysed it in some detail with Crystal 8 (Stockfish prunes too aggressively it seems to solve even some of the side lines in reasonable time). For Crystal, I played the first two moves myself, but all moves by black are forced, so the mates below are proven. After the second white move, blacks has 8 legal moves, all leading to mate. The longest mate is M27 (first two moves included). Below are the details:
After
Now black has 8 legal moves:
2a. ... c7c5 8/1r4p1/1p1P4/1Pp5/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - c6 0 3 M9 info depth 19 seldepth 21 multipv 1 score mate 9 nodes 108804985 nps 51274733 hashfull 0 tbhits 0 time 2122 pv d3d4 b1a2 f3b7 c5d4 c4d4 g7g5 d6d7 g5f4 d7d8q f4f3 b7f3 c1b1 f3e4 b1c1 d4e5 c1b1 d8d1
2b. ... g7g6 8/1rp5/1p1P2p1/1P6/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - - 0 3 M13 info depth 46 seldepth 29 multipv 1 score mate 13 nodes 21329975530 nps 55213517 hashfull 55 tbhits 0 time 386318 pv f4e2 c1d1 e2g3 d1c1 f3b7 c7d6 g3f1 d6d5 b7d5 b1a2 d5f3 c1b1 f1d2 b1c1 a4a5 b6a5 b5b6 a5a4 b6b7 g6g5 b7b8q a4a3 b8h8 a3b2 h8h1
2c. ... g7g5 8/1rp5/1p1P4/1P4p1/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - g6 0 3 M13 info depth 46 seldepth 37 multipv 1 score mate 13 nodes 13446404457 nps 49849870 hashfull 42 tbhits 0 time 269738 pv f3b7 c7d6 f4g2 b1a2 d3d4 d6d5 b7d5 c1d1 d5f3 d1c1 g2e3 c1b1 f3e4 b1c1 e4f5 a2b1 d4d5 b1a2 d5d6 c1b1 d6d7 b1c1 d7d8q c1b1 d8d1
2d. ... c7c6 8/1r4p1/1ppP4/1P6/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - - 0 3 M17 info depth 39 seldepth 33 multipv 1 score mate 17 nodes 15854011700 nps 39410781 hashfull 178 tbhits 0 time 402276 pv f4e2 c1d1 e2d4 d1c1 b5c6 b6b5 c4c5 b5b4 d4e2 c1d1 c6b7 b4c3 d6d7 c2c1q e2c1 d1c1 d7d8q b1c2 d8d4 c1b1 d4c3 b1c1 b7b8q c1b1 b8h2 b1a2 h2g1 g7g6 c3b4 a2b2 b4d4 b2a2 g1a1
2e. ... c7d6 8/1r4p1/1p1p4/1P6/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - - 0 3 M13 info depth 24 seldepth 45 multipv 1 score mate 13 nodes 6085943519 nps 38857526 hashfull 19 tbhits 0 time 156622 pv f4e2 c1d1 e2g3 d1c1 f3b7 b1a2 g3f1 c1d1 b7f3 d1c1 f1d2 d6d5 c4d5 g7g6 a4a5 b6a5 b5b6 a5a4 b6b7 g6g5 b7b8q a2b1 b8h2 b1a2 h2g1
2f. ... b7a7 8/r1p3p1/1p1P4/1P6/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - - 1 3 M20 info depth 57 seldepth 53 multipv 1 score mate 20 nodes 331706115364 nps 33407046 hashfull 998 tbhits 0 time 9929226 pv d3d4 b1a2 d6d7 c1b1 f3e4 a7a4 c4d5 a4a8 f4g6 b1c1 d5e6 a8g8 e6e7 c1d1 e4f3 d1c1 g6e5 c7c6 b5c6 c1b1 e5c4 g8a8 f3e4 a8h8 d7d8q h8d8 e7d8 g7g6 c6c7 b1c1 c7c8q c1d1 e4f3 d1c1 c4a3 b6b5 c8e6 g6g5 e6e1
2g. ... b7b8 1r6/2p3p1/1p1P4/1P6/P1K2NP1/1pBP1B2/1Pp5/nbk5 w - - 1 3 M25 info depth 60 seldepth 51 multipv 1 score mate 25 nodes 14913945522976 nps 48809971 hashfull 1000 tbhits 0 time 305551205 pv d3d4 b1a2 d6c7 b8f8 f4d3 c1b1 f3b7 c2c1b d3c1 b1c1 c7c8q f8c8 b7c8 a1c2 d4d5 c2a3 c4d4 a3c2 d4d3 a2b1 d3e2 c2a1 d5d6 b1c2 d6d7 c2d1 e2f2 c1b1 d7d8q d1c2 d8d5 b1a2 f2e3 c2g6 e3d2 a2b1 a4a5 g6c2 d5h1 b1a2 a5b6 c2d1 d2c1 d1f3 h1f3 a1c2 f3a8 c2a3 a8a3
2h. ... b1a2 8/1rp3p1/1p1P4/1P6/P1K2NP1/1pBP1B2/bPp5/n1k5 w - - 1 3 M21 info depth 58 seldepth 41 multipv 1 score mate 21 nodes 769737196880 nps 45432662 hashfull 999 tbhits 0 time 16942375 pv f3b7 c1b1 f4e2 c2c1q e2c1 c7d6 a4a5 b6a5 b7e4 a1c2 b5b6 c2e3 c4b5 d6d5 e4f3 b1c1 b6b7 e3c2 f3d5 c2e3 d5f3 a2b1 b7b8q b1d3 b5a5 c1c2 b8a7 e3f1 a5b4 f1h2 a7f2 c2b1 f3d5 h2f3 f2f3 d3c2 d5b3 b1a1 b3c2 a1a2 f3a8
Longest mate is the 2 ... b7b8 variation M25, or thus M27 for the complete PV:
g6f4 a2a1N d5d6 b7b8 d3d4 b1a2 d6c7 b8f8 f4d3 c1b1 f3b7 c2c1b d3c1 b1c1 c7c8q f8c8 b7c8 a1c2 d4d5 c2a3 c4d4 a3c2 d4d3 a2b1 d3e2 c2a1 d5d6 b1c2 d6d7 c2d1 e2f2 c1b1 d7d8q d1c2 d8d5 b1a2 f2e3 c2g6 e3d2 a2b1 a4a5 g6c2 d5h1 b1a2 a5b6 c2d1 d2c1 d1f3 h1f3 a1c2 f3a8 c2a3 a8a3