Winning endgame for black?

[Nordlandia]

Stockfish evaluates it as -1.5 - 1.75 for black.

[d]r7/p2k1pp1/2nb3p/2p5/8/8/PP3P1P/3Q1K2 w - - 0 30

I played this casual bullet game on lichess just some minutes ago and the Q vs RBN imbalance did turn out to be interesting.

[pgn][Event "Casual Bullet game"] [Site "https://lichess.org/VxBLEFnC"] [Date "2019.07.06"] [Round "?"] [White "Anonymous"] [Black "Anonymous"] [Result "0-1"] [ECO "A04"] [PlyCount "70"] [EventDate "2019.??.??"] 1. Nf3 b6 2. e4 Bb7 3. Nc3 c5 4. d4 cxd4 5. Nxd4 e6 6. Bc4 Nf6 7. Nf3 Nxe4 8. Nxe4 Bxe4 9. Bd3 Bxd3 10. Qxd3 Nc6 11. Ng5 h6 12. Nf3 d5 13. Be3 e5 14. Bd2 e4 15. Qb3 exf3 16. O-O fxg2 17. Kxg2 Qg5+ 18. Kh1 Qf5 19. Rfe1+ Kd7 20. c4 d4 21. Rad1 Bd6 22. Be3 Qf3+ 23. Kg1 Qg4+ 24. Kf1 Rhe8 25. Bxd4 Rxe1+ 26. Rxe1 Qxd4 27. Rd1 Qg4 28. c5 Qxd1+ 29. Qxd1 bxc5 30. Ke2 Nd4+ 31. Kd2 Rb8 32. Kc3 Re8 33. b4 Be5 34. Kc4 cxb4 35. Kxb4 Kd6 0-1 [/pgn]

[zullil]

Likely winning for Black, according to Cfish with 6-man tables:

-2.36 30. Qg4+ Kc7 31. Qxg7 Rd8 32. Qxh6 Be5 33. Qc1 Kb6 34. h4 Rd6 35. Qe3 Rf6 36. Qb3+ Kc7 37. h5 Bd4 38. Qg3+ Kd7 39. f3 Ke8 40. a4 Kf8 41. b3 Nb4 42. Qg4 a5 43. Ke2 Nd5 44. Kd2 Be3+ 45. Ke2 Re6 46. Kd3 Re5 47. Kc4 Bh6 48. Qc8+ Kg7 49. Qg4+ Kh7 50. Qg3 Rxh5 51. Kxc5 Bf4 52. Qe1 Nb4+ 53. Kb6 Re5 54. Qd1 Kg7 55. Kb7 Rd5 56. Qg1+ Kf8 57. Qg4 Be5 58. Qe4 Rc5 59. Qh4 Nc6 60. Kb6 Rc3 61. Qe4 Bd4+ 62. Ka6 Rc5 63. Qh4 Nb4+ 64. Kb7 Be3 65. Qd8+ Kg7 66. f4 Rd5 67. Qh4 Bd4 68. Kc7 Bf6 (depth 60, 2:04:20)

[Nordlandia]

I'm downloading KRBNPvKQ and KRBNvKQP table that might turn the tide of analysis.

[Ajedrecista]

Hello:

I'm downloading KRBNPvKQ and KRBNvKQP table that might turn the tide of analysis.

Good luck! Assuming that you have all sub-7 tablebases, don't forget the pawnless tablebases related to KRBNPvKQ and KRBNvKQP, that is, if the pawn promotes and is not captured.

http://tablebase.lichess.ovh/tables/sta ... 2_pawnless

Code: Select all

P -> {Q, N, R, B}

KQRBNvKQ

KRBNNvKQ
KRRBNvKQ
KRBBNvKQ

http://tablebase.lichess.ovh/tables/sta ... 3_pawnless

Code: Select all

P -> {Q, N, R, B}

KRBNvKQQ

KRBNvKQN
KRBNvKQR
KRBNvKQB

Judge the size of underpromotion tables. You might be done with KQRBNvKQ and KRBNvKQQ, added with the pawnful tablebases you are downloading right now.

Regards from Spain.

Ajedrecista.

[Nordlandia]

Ajedrecista

Downloading 200 GB take about half a day at 5 MB/s and is
presumely over in a couple of hours when i'm home from work.

I bet the evaluation should rise in blacks favour. When stockfish can consult 7 piece tables. Those tables i'm downloading will tell. If not good enough i download those sub-related tables just to be sure.