Hard testposition from TCEC

[zullil]

Is the difference I see just because I'm not using tablebases?


[d]r2qkr2/1b1nb1pp/pp1BQ3/8/P1P3P1/8/4BP1P/R2R2K1 w q -

Code: Select all

Engine: Kaissa IV (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

57     1385:49+1.05    22.c5 Rf6 23.Qg8+ Nf8 24.c6 Bxc6 
                       25.Be5 Bd6 26.Bxd6 Rxd6 27.Bf3 Rxd1+ 
                       28.Rxd1 Bxf3 29.Re1+ Qe7 30.Rxe7+ Kxe7 
                       31.Qxg7+ Ke6 32.g5 Bd5 33.f4 Kd6 
                       34.f5 b5 35.Qf6+ (167.594.721.391) 2015 

57     1385:49+0.94    22.g5 Rf7 23.Bh5 g6 24.Bg4 Kf8 
                       25.Rab1 a5 26.h3 Qe8 27.Qxd7 Qxd7 
                       28.Bxd7 Bf3 29.Bxe7+ Kxe7 30.Rd3 Rd8 
                       31.Bf5 Rxd3 32.Bxd3 Rf4 33.Rxb6 Rd4 
                       34.Bf1 Rd1 35.Rb3 (167.594.721.391) 2015 

57     1385:490.00     22.Rac1 Rf6 23.Qg8+ Rf8 (167.594.721.391) 2015

[d]r4n2/3k3p/pp3Q2/3b2P1/P4P2/8/7P/6K1 b - -

Code: Select all

Engine: Kaissa IV (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

49     438:48 +0.56    34...Ne6 35.Qe5 Kc6 36.h4 b5 37.f5 Nc5 
                       38.Qf6+ Kd7 39.axb5 axb5 40.h5 b4 
                       41.g6 h6 42.Qd4 Kc6 43.f6 b3 44.f7 Nd7 
                       45.Qc3+ Kd6 46.Qc1 Ra2 47.g7 Bxf7 (56.168.186.704) 2133 

48     438:48 +0.89    34...b5 35.f5 Kc7 36.h4 Nd7 37.Qc3+ Kd6 
                       38.Qg3+ Kc6 39.h5 b4 40.h6 Rg8 41.g6 b3 
                       42.a5 Nc5 43.Qe5 Be4 44.Kh2 hxg6 
                       45.h7 Rf8 46.fxg6 Bxg6 47.h8R Rxh8+ (56.168.186.704) 2133 

48     438:48 +1.16    34...Kc7 35.h4 Nd7 36.Qf5 Bg8 
                       37.Qc2+ Kd8 38.f5 Rb8 39.f6 b5 
                       40.Qf5 b4 41.f7 Bxf7 42.Qxf7 b3 
                       43.Qxh7 b2 44.Qb1 Ne5 45.Kg2 Ng6 
                       46.Kg3 Rb3+ 47.Kh2 Ne5 (56.168.186.704) 2133 

48     438:48 +1.67    34...Ng6 35.Qd4 Kc6 36.f5 Nh8 
                       37.Qf6+ Kc5 38.Qe7+ Kd4 39.Qg7+ Ke3 
                       40.Qe5+ Be4 41.Qg3+ Kd4 42.Qd6+ Bd5 
                       43.Qf4+ Kc5 44.Qc7+ Kd4 45.Qxh7 Nf7 
                       46.Qh4+ Ke3 47.Qg3+ Ke4 (56.168.186.704) 2133

Hi Eelco,

Here's what I see so far with Cfish-dev and 6-man tables, for the position occurring after c5 Rf6 Qg8+ Nf8 c6 Bxc6 Be5:
[d]r2qknQ1/4b1pp/ppb2r2/4B3/P5P1/8/4BP1P/R2R2K1 b q - 1 4

+0.89 [+] [*] 4... Bd6 5. Bxd6 Rxd6 6. Bf3 Rxd1+ 7. Rxd1 Bxf3 8. Re1+ Qe7 9. Rxe7+ Kxe7 10. Qxg7+ Ke6 11. g5 Bd5 12. f4 Kd6 13. h4 b5 14. Qe5+ Kc6 15. Qc3+ Bc4 16. Qa5 Kb7 17. Qe1 Kc6 18. h5 Ne6 19. h6 Nc5 20. Qc3 Rg8 21. Qf6+ Ne6 22. g6 Rxg6+ 23. Qxg6 hxg6 24. h7 Nxf4 25. h8=Q Nd5 26. Qc8+ Kb6 27. axb5 axb5 28. Kf2 Bd3 29. Qf8 Kc6 30. Qa3 Bc4 31. Qa8+ Kc5 32. Qa7+ Kb4 33. Qd4 g5 34. Kf3 Kb3 (depth 45, 1:03:52)

+0.91 [+] [*] 4... Rd6 5. Bxd6 Bxd6 6. Rac1 Rc8 7. Rc3 Qf6 8. Rxd6 Qxc3 9. Re6+ Kd8 10. Qxf8+ Kc7 11. Re7+ Kb8 12. Qf4+ Ka8 13. Bxa6 Rd8 14. Qf7 Rd1+ 15. Bf1 Rxf1+ 16. Kxf1 Qd3+ 17. Re2 Qh3+ 18. Ke1 Qc3+ 19. Rd2 Bf3 20. Qe8+ Ka7 21. Qd7+ Kb8 22. Qd4 Qc1+ 23. Rd1 Bxd1 24. Qxd1 Qf4 25. Qd8+ Ka7 26. Qd7+ Ka6 27. Qc6 Ka7 28. h3 h6 29. Kf1 Qh2 30. Qd7+ Ka6 31. Qd3+ Ka7 32. Qe3 Qh1+ 33. Ke2 Ka6 34. Qd3+ Kb7 35. Qd7+ Ka6 36. Qb5+ Ka7 37. Qb4 Ka6 38. Qc4+ Kb7 39. Qd3 Qc6 40. Qd4 g5 41. Ke3 Ka6 42. f4 Qc1+ 43. Kf2 gxf4 (depth 45, 1:03:52)

Will let the MultiPV=2 search continue, but certain not seeing any win.

[Eelco de Groot]

Hi Louis, thank you very much for the test. I could not do that without installing all those tablebases. I suspected it was not really the best of testpositions but I heard nothing from the other contributors in the thread or anyone else. And if Stockfish really found a win that would be interesting but it could also mean there was something wrong in recent changes in Stockfish or I should throw this Kaissa out of the window. Not yet