Stockfish can not win this game

[Damir]

By all chess rules, the game should be a draw...

[pgn][Event "TCEC Season 28 - Viewer Submitted Openings Bonus 28"]
[Site "https://tcec-chess.com"]
[Date "2025.06.20"]
[Round "10.1"]
[White "Stockfish dev-20250602-5337edfd"]
[Black "Berserk 20250606"]
[Result "*"]
[Annotator "live"]

1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 4. Nbd2 O-O 5. g3 d5 6. Qc2 c6 7. Bg2 b5 8. c5 Nbd7 9. O-O a5 10. a3 Bxd2 11. Bxd2 Ne4 12. Bf4 f6 13. b4 h6 14. Nd2 Nxd2 15. Bxd2 a4 16. e4 f5 17. e5 Rf7 18. h4 g5 19. Rae1 Ra7 20. Qc1 Rg7 21. hxg5 hxg5 22. Bf3 f4 23. Bg4 Nf8 24. Kg2 Rh7 25. Rh1 Rag7 26. Reg1 Ng6 27. gxf4 Rh4 28. Kf1 Qe8 29. fxg5 Rgh7 30. Rxh4 Rxh4 31. Ke2 Kf8 32. Rg3 Ne7 33. Qc3 Qg6 34. Qf3+ Kg8 35. Rh3 Rxh3 36. Qxh3 Nf5 37. Be3 Bd7 38. Bh5 Be8 39. Bxg6 Bxg6 40. Ke1 Kg7 41. Bc1 Kg8 42. Be3 Kg7 43. Bd2 Kg8 44. Bc1 Kg7 45. Be3 Kg8 46. Bc1 Kg7 47. Bd2 Kg8 48. Bf4 Kg7 49. Bc1 Kg8 50. Bd2 Kg7 51. Be3
*[/pgn]

[Ajedrecista]

Hello:

Great example of fortress! Black pieces' duties are clear after 35.- ..., Be8!!; 36.- Bxg6, Bxg6: since the white pawns block the white DSB, the black night must stand in its outpost of f5 (light square, safe from the white DSB), covering h6 from the white queen; the black LSB must cover h5 from the white queen (also h7, eventually) and the black king must cover h7 and h8 from the white queen, hence switching between g7 and g8.

------------

It resembles pretty much like this fortress from a game of 1905:

[pgn][Event ""]
[Site "Vienna"]
[Round "17"]
[Date "1905.03.06"]
[White "Neumann"]
[Black "Nimzowitsch"]
[Result "1/2-1/2"]
[SetUp "1"]
[FEN "3b4/3b1k2/1p1p4/p1pNp1p1/P1P1P1P1/1PB2PK1/8/8 w - - 0 51"]

51. Bxe5 dxe5 52. Nxb6 Bxb6 1/2-1/2[/pgn]

The black extra bishop pair is useless in this other example.

Regards from Spain.

Ajedrecista.

[jefk]

the move ... Bb4 wasn't good (...d5 was the best book move)

after g3 (catalan) the move to play is ... Bb4+
not after Nf3

https://sourceforge.net/projects/bookbu ... release44/