TCEC position: can black draw this position ?

[JuLieN]

Big discussion on TCEC about the following position (Komodo vs Stockfish) :

[d]8/5k2/bP4p1/2B4p/5K1P/4P3/6P1/8 b - - 2 55
Can black save the game and draw ?

EDIT:

[IGarcia]

I think is not possible to draw.

I played this position, me white, black komodo 6. Its easy wining plan,
even I didn't play best moves. Seems SF defends worst than komodo as showed in game.

[pgn]
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "human rookie"]
[Black "Komodo 6"]
[Result "*"]
[FEN "8/5k2/bP4p1/2B4p/5K1P/4P3/6P1/8 b - - 2 55"]

55...Bb7 56.g3 Ke8 57.Kg5 Kd7 58.Kxg6 Bf3 59.Bd4 Kd6 60.Kf5 Bb7 61.Kg5 Bf3
62.Kh6 Kd7 63.Be5 Kc6 64.Bc7 Be2 65.Kg5 Kb7 66.e4 Bd1 67.e5 Bg4 68.e6 Bxe6
69.Kxh5 Bd5 70.Kg5 Bf3 71.h5 Bd5 72.h6 Be4 73.Kf6 Bh7 74.g4 Be4 75.g5 Bh7
76.Kg7 Bd3 77.h7 Bxh7 78.Kxh7 Kc6 79.g6 Kb7 80.g7 Ka6 81.g8=Q Kb7 *
[/pgn]

[gerold]

No. White has a pass pawn.

Best,
Gerold.

[kgburcham]

[D] 8/5k2/bP4p1/2B4p/5K1P/4P3/6P1/8 b - -

small hardware 6 core
still running, now I will check this line

Engine: Stockfish 111113 64 SSE4.2 (4096 MB)
by Tord Romstad, Marco Costalba and Joona
38/39 0:00 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc7 Bd5 (11.075.963) 12643
39/42 0:01 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc5 Bc6 (14.182.459) 12952
40/42 0:01 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc5 Bc6 (17.700.742) 13160
41/42 0:01 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc5 Bc6 (19.188.443) 13197
42/42 0:01 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc5 Bc6 (21.285.742) 12963
43/42 0:02 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc5 Bc6 (24.721.411) 12354
44/42 0:02 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.g3 Bc6 8.Kd4 Bb7 9.e5 Ke6 10.Bd6 Bd5 11.Bc5 Bb7 12.Ba3 Bd5 13.Bd6 Bb7 14.Bc5 Bc6 (30.300.744) 11967
45/51 0:03 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Bc6 13.Bg5 Bb7 14.Ke3 Kd7 (44.174.645) 12560
46/51 0:04 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Bc6 13.Bg5 Bb7 14.Ke3 Kd7 (51.127.240) 12778
47/51 0:04 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Kf6 13.Be3 Ke6 14.Bg5 Kd6 (58.557.094) 12963
48/51 0:05 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Kf6 13.Be3 Ke6 14.Bg5 Kd6 (72.091.181) 13409
49/55 0:05 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Kf6 13.Be3 Ke6 14.Bg5 Kd6 (81.148.565) 13592
50/55 0:07 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Kf6 13.Be3 Ke6 14.Bg5 Kd6 (112.139.549) 14265
51/57 0:08 +1.71 1...Ke6 2.Bd4 Bb7 3.e4 Kd6 4.Be5+ Ke7 5.Bc7 Ke6 6.Ke3 Kd7 7.Kd3 Ke6 8.Kd4 Bc6 9.Bg3 Bb7 10.Be5 Ba6 11.Bc7 Bb7 12.Bf4 Kf6 13.Be3 Ke6 14.Bg5 Kd6 (129.464.551) 14433
52/58 0:26 +1.79-- 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Bf3 11.g4 hxg4 12.e6+ Ke7 13.Kxg6 Kxe6 14.Kg7 g3 (411.336.351) 15520
52/58 0:29 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Kf8 11.b7 Bxb7 12.Kxg6 Bf3 13.Kf6 Bg4 14.Ba3+ Ke8 (466.790.807) 15763
53/59 0:31 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Kf8 11.b7 Bxb7 12.Kxg6 Bf3 13.Kf6 Bg4 14.Ba3+ Ke8 (503.864.577) 15813
54/59 0:34 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Kf8 11.b7 Bxb7 12.Kxg6 Bf3 13.Kf6 Bg4 14.Ba3+ Ke8 (554.001.975) 15862
55/59 0:37 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Kf8 11.b7 Bxb7 12.Kxg6 Bf3 13.Kf6 Bg4 14.Ba3+ Ke8 (597.767.167) 15865
56/59 0:43 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Kf8 11.b7 Bxb7 12.Kxg6 Bf3 13.Kf6 Bg4 14.Ba3+ Ke8 (699.554.614) 16080
57/59 0:48 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Bc6 6.e5 Kd5 7.Ba3 Ke6 8.Kg5 Be4 9.Bb2 Kf7 10.Kh6 Kf8 11.b7 Bxb7 12.Kxg6 Bf3 13.Kf6 Bg4 14.Ba3+ Ke8 (773.519.371) 16092
58/59 0:51 +1.83 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Kf6 6.Bd6 Ke6 7.e5 Bd5 8.Kg5 Be4 9.Kh6 Kf7 10.Bb4 Ke6 11.Bc3 Kf7 12.Bb2 Kf8 13.b7 Bxb7 14.Kxg6 Bf3 (828.294.682) 16111
59/66 0:58 +1.91-- 1...Ke6 2.Bd4 Bb7 3.g3 Bd5 4.Bc5 Bb7 5.e4 Kf6 6.e5+ Ke6 7.Bg1 Bd5 8.Bd4 Bb7 9.Kg5 Be4 10.Kh6 Ke7 11.Kg7 Ke6 (947.753.188) 16247
59/67 1:03 +2.00-- 1...Ke6 2.Bd4 Bb7 3.g3 Kd7 4.Ke5 Bc6 5.e4 Bb7 6.Bg1 Kd8 7.Kf4 Ke7 8.Bd4 Kf8 9.Bc3 Kf7 10.Bd4 Ke7 11.e5 Ke6 12.Kg5 Be4 13.Kh6 Kf7 14.Be3 Ke6 (1.026.732.710) 16287
59/67 1:07 +2.12-- 1...Ke6 2.Bd4 Bb7 3.g3 Ba8 4.Bb2 Bc6 5.e4 Bb7 6.Bd4 Ke7 7.e5 Ke6 8.Kg5 Be4 9.Kh6 Kf7 10.Be3 Ke6 11.Bf4 Ke7 (1.096.851.438) 16357
59/67 1:09 +2.30-- 1...Ke6 2.Bd4 Bb7 3.g3 Kd5 4.Kg5 Ke4 5.Kxg6 Kf3 6.Kxh5 Kxg3 7.Kg5 Be4 8.h5 Bb7 9.h6 Be4 10.b7 Bxb7 11.h7 (1.137.776.174) 16340
59/67 1:28 +2.57-- 1...Ke6 2.Bd4 Bb7 3.g3 Bc8 4.Bc5 Kd5 5.Kg5 Kxc5 6.Kxg6 Kc6 7.Kxh5 Kxb6 8.Kg5 Kc6 9.h5 Kd6 10.h6 Ke6 11.h7 (1.415.000.235) 16035
59/67 1:52 +2.98-- 1...Ke6 2.Bd4 Bb7 3.g3 Ba8 4.Be5 Kd5 5.e4+ Kc5 6.Bc7 Bc6 7.e5 Kb5 8.Kg5 Ka6 9.Kxg6 Be8+ 10.Kg5 Kb7 11.Kf6 Bc6 12.e6 Bb5 13.e7 Bd7 14.Kf7 (1.814.752.018) 16152
59/67 1:59 +3.59-- 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Bf6 Ba8 6.Kxg6 Bf3 7.Bd4 Kc6 8.Kg5 Kd7 9.e4 Kd6 10.Kg6 Kc6 11.e5 Kd7 12.e6+ Kxe6 13.g4 Bxg4 14.b7 Bf5+ (1.919.917.513) 16102
59/69 2:06 +4.51-- 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Bf6 Ke6 6.Bb2 Kd6 7.Kf4 Ba8 8.Be5+ Kc6 9.Bc7 Kd7 10.Kg5 Be4 11.Be5 Ke8 12.Kf4 Bb7 13.Bb2 Kf7 14.Ba1 Ke8 (2.044.067.274) 16159
59/71 2:16 +4.51 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Bf6 Ke6 6.Bb2 Kd6 7.Kf4 Ba8 8.Be5+ Kc6 9.Bc7 Kd7 10.Kg5 Be4 11.Be5 Ke8 12.Kf4 Bb7 13.Bb2 Kf7 14.Ba1 Ke8 (2.217.842.914) 16227
60/71 2:23 +4.51 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Bf6 Ke6 6.Bb2 Kd6 7.Kf4 Ba8 8.Be5+ Kc6 9.Bc7 Kd7 10.Kg5 Be4 11.Be5 Ke8 12.Kf4 Bb7 13.Bb2 Kf7 14.Ba1 Ke7 (2.332.125.530) 16255
61/72 2:31 +4.51 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Bf6 Ke6 6.Bb2 Kd6 7.Kf4 Ba8 8.Be5+ Kc6 9.Bc7 Kd7 10.Kg5 Be4 11.Be5 Ke8 12.Kf4 Bb7 13.Bb2 Kf7 14.Ba1 Ke7 (2.464.878.900) 16231
62/72 2:45 +4.51 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Bf6 Ke6 6.Bb2 Kd6 7.Kf4 Ba8 8.Be5+ Kc6 9.Bc7 Kd7 10.Kg5 Be4 11.Be5 Kc6 12.Kf4 Bg2 13.Bd4 Bh1 14.e4 Kd7 (2.692.830.657) 16269
63/75 3:12 +4.42++ 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 (3.164.651.465) 16459
63/75 3:26 +4.34++ 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 (3.361.000.307) 16259
63/75 3:38 +4.22++ 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 (3.532.687.627) 16170
63/75 4:15 +4.04++ 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 (3.822.908.842) 14977
63/75 4:30 +4.59-- 1...Ke6 2.Bd4 Kd6 3.Kg5 Bd3 4.g3 Be4 5.Kf4 Bb7 6.e4 Ke6 7.e5 Bg2 8.Kg5 Be4 9.Kh6 Kf5 10.Bc3 Ke6 11.Kg7 Ke7 12.Bb4+ Ke6 13.Bc5 Kxe5 14.Kf7 Kf5 (4.053.952.038) 14995
63/75 4:40 +5.00-- 1...Ke6 2.Bd4 Kd7 3.e4 Ke6 4.Kg5 Kf7 5.e5 Bb7 6.g4 hxg4 7.e6+ Kxe6 8.Kxg6 Kd5 9.Bf2 Ke4 10.Bg1 Kf3 11.h5 Bd5 12.h6 Kg2 13.h7 Be4+ 14.Kg7 Bxh7 (4.210.616.057) 15026
63/75 4:49 +5.61-- 1...Ke6 2.Bd4 Bc8 3.Kg5 Kf7 4.e4 Bb7 5.Kf4 Ke6 6.g3 Kf7 7.Ke5 Ke7 8.Bc5+ Kd7 9.Kf4 Ke6 10.e5 Bd5 11.Kg5 Be4 12.Bd4 Kf7 13.Ba1 Bf3 14.Kh6 Bd5 (4.346.228.711) 15031
63/75 4:53 +6.52-- 1...Ke6 2.Bd4 Bb7 3.Kg5 Kf7 4.g3 Bd5 5.Bc5 Bc6 6.Kf4 Bg2 7.e4 g5+ 8.hxg5 (4.421.501.854) 15041
63/75 5:45 +7.89-- 1...Ke6 2.Bd4 Bb7 3.Kg5 Kf7 4.g3 Bd5 5.Bc5 Bc6 6.Kf4 Bd5 7.e4 Bb7 8.Ke5 Bc6 9.Kd6 Bb7 10.e5 Bc8 11.e6+ Ke8 12.e7 g5 13.hxg5 Bh3 14.b7 (4.712.590.515) 13636
63/76 6:36 +9.94-- 1...Ke6 2.g3 Kd5 3.Bd4 Ke6 4.e4 Bb7 5.e5 Ke7 6.Kg5 Be4 7.Kh6 Kf7 8.Bc5 Ke6 9.Kg7 Kxe5 10.Kf7 Kf5 11.Be3 Bd5+ 12.Ke7 Ke4 13.Kd6 Kxe3 14.Kxd5 Kd3 (5.585.300.503) 14071
63/76 7:16 +13.02-- 1...Ke6 2.g3 Kd5 3.Bd4 Bb7 4.Kg5 Kc4 5.Kxg6 Bf3 6.Kg5 Be4 7.Kxh5 Kb4 8.Kg5 Kb5 9.Kf4 Bc6 10.g4 Ka6 11.e4 Bb7 12.Kg5 Bxe4 13.Kh6 Kb7 14.g5 Ka6 (6.272.774.423) 14361
63/87 8:13 +17.63-- 1...Ke6 2.g3 Kd5 3.Bd4 Kd6 4.e4 Bb7 5.e5+ Kd7 6.Be3 Bg2 7.Kg5 Be4 8.Kf6 Kd8 9.Bd4 Bc6 10.Kxg6 Ke7 11.Kxh5 Bf3+ 12.g4 Kd8 13.Bc5 Kd7 14.e6+ Kxe6 (7.233.912.568) 14657

[JuLieN]

@Kim:
I have SF4 searching this pos for 22 minutes, now (currently at depth 66) So we're doubling our efforts. Maybe you can try with K6 or H3/4 if you have them ? (I don't)

[kgburcham]

@Kim:
I have SF4 searching this pos for 22 minutes, now (currently at depth 66) So we're doubling our efforts. Maybe you can try with K6 or H3/4 if you have them ? (I don't)

still working on it, checking different lines.
kgburcham

[michiguel]

Big discussion on TCEC about the following position (Komodo vs Stockfish) :

[d]8/5k2/bP4p1/2B4p/5K1P/4P3/6P1/8 b - - 2 55
Can black save the game and draw ?

EDIT:

Yes, white wins. When we were talking I missed a detail. Spamme pointed out Kg7 in the line below.

You need to reach this position
[D]8/5k2/1P4p1/4P1K1/3Bb2P/8/8/8 w - - 5 77

With the bishop in d4 or c3, NOT in d6.

So, in this position white wins with Kh6. Zugzwang. If Ke6, Kg7! wins penetrating f8 --> e8. If Bb7, e6+! (now g6 falls). B has to stay in e4, so the King needs to move. If Kf8, then b7 Bxb7 and Kxg6 wins.

The position above is easy to reach playing g4 at one point.

Miguel
EDIT: SF committed suicide in the game and made things easier. If an engine does not disable nullmove here, it could be in trouble seeing the win.

[IGarcia]

Yes, white wins. When we were talking I missed a detail. Spamme pointed out Kg7 in the line below.

You need to reach this position
[D]8/5k2/1P4p1/4P1K1/3Bb2P/8/8/8 w - - 5 77

With the bishop in d4 or c3, NOT in d6.

So, in this position white wins with Kh6. Zugzwang. If Ke6, Kg7! wins penetrating f8 --> e8. If Bb7, e6+! (now g6 falls). B has to stay in e4, so the King needs to move. If Kf8, then b7 Bxb7 and Kxg6 wins.

The position above is easy to reach playing g4 at one point.

Miguel
EDIT: SF committed suicide in the game and made things easier. If an engine does not disable nullmove here, it could be in trouble seeing the win.

In the game, SF moved his king towards b pawn, and its very bad because the 2 black pawns will fall. Better defense is to keep the king warding g6 and bishop de main white diagonal.

The position you show its tricky, and maybe the best defense for black, but engines like to walk with the king to control b pawn. (at least at fast time control)

Ignacio.

[Dirt]

SF committed suicide in the game and made things easier.

That's still a problem. I have no idea how to fix it, though.

[MikeGL]

Blacks king seems to be a bit late by a few tempo.
If Blacks king controlled e4 square then surely it's a
draw even if two pawns up for white and has the move.

[D]8/1b6/1P4p1/2B1k2p/7P/4P1K1/6P1/8 w - - 2 55

Problem with the actual position (from the game) is that b7, e6 and g6,
although all are light squares, at least two of those points should be aligned.
And in my modified position, instead of defending e6 (for the passed pawn),
defend e4 square (which is aligned to b7).