Bishops endgame.

[Ajedrecista]

Hello!

I played today against a 2174 Elo guy (if I am not wrong) in a simultaneous event. He was white and played a Blackmar-Diemer Gambit, so I went a pawn ahead during all the game. I have analyzed the game with Houdini, using Multi PV = 3 under Arena... I am happy in the sense that I did not blunder seriously into a lost position in any move and finally I got a draw! It is a truly achievement for me. I also had some winning chances according to Houdini (over +2 in eval, in my favour) at move 31, but I blew it at move 32 because it was too difficult for me and even I did not calculated it: my style is VERY dull; I offered a draw to this guy in move 34 and he kindly accepted it.

The position looks drawish with a small plus for me, given my extra pawn. Here is the final position, where a draw was agreed:

[d]4b1k1/7p/p1p2p1P/1pP3p1/3PBpP1/8/PP6/1K6 b - - 1 34

34.- ..., Bg6 was tempting for me but I rightly saw that it was losing, so I thought about 34.- ..., Bd7 (which is also the choice of Houdini), but I preferred to secure the draw. My question about this position is the next one: is it a dead draw or black can find a winning plan? I briefly analyzed this position with Houdini and it returns around -0.25 evals in my PC at depths > 20, but it also shows depths with '+' (e.g. 27/65+) around -0.5 at maximum. This is why I ask here: because more powerful computers would not have any problem. Thanks in advance for your attention.

Regards from Spain.

Ajedrecista.

[Dicaste]

Code: Select all

New game
4b1k1/7p/p1p2p1P/1pP3p1/3PBpP1/8/PP6/1K6 b - - 0 1

Analysis by Rampage v2.75.64 x64:

34...f5 35.Bxf5 f3 36.Kc1 Bf7 37.a3 f2 38.Bd3 Be6 
  =/+  (-0.68)   Depth: 7/21   00:00:00  7kN
34...f5 35.Bxf5 f3 36.Kc1 f2 37.Bd3 Bd7 38.Kd2 Bxg4 39.Ke3 Bf5 
  =/+  (-0.57)   Depth: 8/21   00:00:00  10kN
34...Bd7 
  =/+  (-0.64 ++)   Depth: 9/21   00:00:00  18kN
34...Bd7 35.Kc2 f5 36.gxf5 Kf7 37.f6 g4 38.Bxh7 f3 39.Bd3 Kxf6 40.Kd2 g3 41.Ke3 f2 42.Kf3 Bf5 43.Kxg3 Bxd3 44.Kxf2 
  =/+  (-0.63)   Depth: 9/26   00:00:00  23kN
34...Bd7 35.Kc2 f5 36.gxf5 Kf7 37.f6 g4 38.Bxh7 f3 39.Bd3 Kxf6 40.Kd2 g3 41.Ke3 f2 42.Kf3 Bf5 43.Kxg3 Bxd3 44.Kxf2 
  =/+  (-0.63)   Depth: 10/26   00:00:00  28kN
34...Bd7 35.Kc2 
  =/+  (-0.57 --)   Depth: 11/31   00:00:00  42kN
34...Bd7 35.Kc2 
  =/+  (-0.44 --)   Depth: 11/35   00:00:00  72kN
34...Bd7 
  =/+  (-0.69 ++)   Depth: 11/36   00:00:00  114kN
34...Bd7 35.Kc2 Kf7 36.Bxh7 Bxg4 37.Be4 Bd7 38.d5 cxd5 39.Bxd5+ Kg6 40.c6 Bf5+ 41.Kd2 Kxh6 42.c7 Kg6 43.Ke2 g4 
  =/+  (-0.31)   Depth: 11/36   00:00:00  207kN
34...Bd7 35.Kc2 
  =/+  (-0.26 --)   Depth: 12/36   00:00:00  263kN
34...Bd7 35.Kc2 f5 36.gxf5 Kf7 37.f6 g4 38.Bxh7 f3 39.Bd3 Kxf6 40.Kd2 g3 41.Ke3 Bg4 42.Be4 f2 43.Bg2 Be6 44.Kf4 Bc4 45.Kxg3 f1Q 46.Bxf1 Bxf1 47.Kf4 Kg6 48.d5 cxd5 49.c6 Kxh6 50.c7 
  =/+  (-0.33)   Depth: 12/40   00:00:00  356kN
34...Bd7 35.Kc2 
  =/+  (-0.28 --)   Depth: 13/40   00:00:00  379kN
34...Bd7 35.Kc2 f5 36.gxf5 Kf7 37.f6 g4 38.Bxh7 f3 39.Bd3 Kxf6 40.Kd2 g3 41.Ke3 Bg4 42.Be4 f2 43.Bg2 Bf5 44.Kf4 Bd3 45.Kxg3 f1Q 46.Bxf1 Bxf1 47.Kf4 Kg6 48.d5 cxd5 49.c6 Kxh6 50.c7 
  =/+  (-0.33)   Depth: 13/40   00:00:00  430kN
34...Bd7 35.Kc2 
  =/+  (-0.28 --)   Depth: 14/40   00:00:00  503kN
34...Bd7 
  =/+  (-0.37 ++)   Depth: 14/40   00:00:00  822kN
34...Bd7 35.Kc2 Bxg4 36.Bxc6 Kf7 37.Kd3 Bf5+ 38.Ke2 g4 39.b4 Ke7 40.Bb7 Kd7 41.d5 Be4 42.Bxa6 Bxd5 43.Bxb5+ Bc6 44.Bxc6+ Kxc6 
  =/+  (-0.26)   Depth: 14/40   00:00:00  880kN
34...Bd7 
  =/+  (-0.30 ++)   Depth: 15/40   00:00:00  1117kN
34...Bd7 35.Kc2 Bxg4 36.Bxc6 Kf7 37.Kd3 Bf5+ 38.Ke2 g4 39.b4 Bb1 40.a3 Ke7 41.d5 f5 42.Bb7 Ba2 43.Bxa6 Bc4+ 44.Kf2 g3+ 45.Kf3 Bxd5+ 46.Kxf4 
  =/+  (-0.27)   Depth: 15/40   00:00:00  1170kN
34...Bd7 35.Kc2 
  =  (-0.23 --)   Depth: 16/40   00:00:00  1664kN
34...Bd7 35.Kc2 Bxg4 36.Bxc6 Kf7 37.Kd3 Be6 38.b3 Bf5+ 39.Ke2 g4 40.b4 Bb1 41.a3 Ke7 42.d5 f5 43.Bb7 Ba2 44.Bxa6 Bc4+ 45.Kf2 g3+ 46.Kf3 Bxd5+ 47.Kxf4 g2 
  =/+  (-0.27)   Depth: 16/40   00:00:01  2370kN
34...Bd7 35.Kc2 Bxg4 36.Bxc6 Kf7 37.Kd3 Be6 38.b3 Bf5+ 39.Ke2 g4 40.b4 Bb1 41.a3 Ke7 42.d5 f5 43.Bb7 Ba2 44.Bxa6 Bc4+ 45.Kf2 g3+ 46.Kf3 Bxd5+ 47.Kxf4 g2 
  =/+  (-0.27)   Depth: 17/40   00:00:01  3187kN
34...Bd7 35.Kc2 Bxg4 36.Bxc6 Kf7 37.Kd3 Be6 38.b3 Bf5+ 39.Ke2 g4 40.b4 Bb1 41.a3 Ke7 42.d5 f5 43.Bb7 Ba2 44.Bxa6 Bc4+ 45.Kf2 g3+ 46.Kf3 Bxd5+ 47.Kxf4 g2 
  =/+  (-0.27)   Depth: 18/45   00:00:01  5075kN
34...Bd7 
  =/+  (-0.32 ++)   Depth: 19/45   00:00:02  7015kN
34...Bd7 
  =/+  (-0.41 ++)   Depth: 19/45   00:00:02  7595kN
34...Bd7 
  =/+  (-0.69 ++)   Depth: 19/45   00:00:03  11537kN
34...Bd7 35.Kc2 Kf7 36.Kd3 f5 37.gxf5 Kf6 38.Ke2 g4 39.Kf2 a5 40.b3 Be8 41.a3 b4 42.axb4 axb4 43.Kg2 Bd7 44.Kf2 Kg5 45.f6 Kxf6 46.d5 cxd5 47.Bxh7 Bc6 48.Bd3 d4 49.h7 g3+ 50.Kf1 Kg7 51.Ke2 Bd5 52.h8R Kxh8 53.Bc4 Bc6 
  =/+  (-0.49)   Depth: 19/47   00:00:04  14366kN
34...Bd7 35.Kc2 Kf7 36.Kd3 f5 37.gxf5 Kf6 38.Ke2 g4 39.Kf2 a5 40.b3 Be8 41.a3 b4 42.axb4 axb4 43.Kg2 Bd7 44.Kf2 Kg5 45.f6 Kxf6 46.d5 cxd5 47.Bxh7 Bc6 48.Bd3 d4 49.h7 g3+ 50.Kf1 Kg7 51.Ke2 Bd5 52.h8R Kxh8 53.Bc4 Bc6 
  =/+  (-0.49)   Depth: 20/47   00:00:04  14914kN
34...Bd7 35.Kc2 
  =/+  (-0.42 --)   Depth: 21/48   00:00:04  17313kN
34...Bd7 35.Kc2 Kf7 36.Kd3 f5 37.gxf5 Kf6 38.Kd2 g4 39.Ke2 Kg5 40.b3 Kf6 41.Kf1 a5 42.Kf2 Be8 43.a3 b4 44.axb4 axb4 45.Kg2 Bd7 46.Kf2 Kg5 47.f6 Kxf6 48.d5 cxd5 49.Bxh7 Bc6 50.Bd3 d4 51.h7 g3+ 52.Kf1 Kg7 53.Ke2 Bd5 54.h8R Kxh8 55.Bc4 Bc6 
  =/+  (-0.49)   Depth: 21/51   00:00:06  24433kN
34...Bd7 35.Kc2 Kf7 36.Kd3 f5 37.gxf5 Kf6 38.Kd2 g4 39.Ke2 Kg5 40.b3 Kf6 41.Kf1 a5 42.Kf2 Be8 43.a3 b4 44.axb4 axb4 45.Kg2 Bd7 46.Kf2 Kg5 47.f6 Kxf6 48.d5 cxd5 49.Bxh7 Bc6 50.Bd3 d4 51.h7 g3+ 52.Kf1 Kg7 53.Ke2 Bd5 54.h8R Kxh8 55.Bc4 Bc6 
  =/+  (-0.49)   Depth: 22/51   00:00:07  28393kN
34...Bd7 35.Kc2 Kf7 36.Kd3 f5 37.gxf5 Kf6 38.Kd2 g4 39.Ke2 Kg5 40.b3 Kf6 41.Kf1 a5 42.Kf2 Be8 43.a3 b4 44.axb4 axb4 45.Kg2 Bd7 46.Kf2 Kg5 47.f6 Kxf6 48.d5 cxd5 49.Bxh7 Bc6 50.Bd3 d4 51.h7 g3+ 52.Kf1 Kg7 53.Ke2 Bd5 54.h8R Kxh8 55.Bc4 Bc6 
  =/+  (-0.49)   Depth: 23/51   00:00:09  35829kN
34...Bd7 35.Kc2 Kf7 36.Kd2 f5 37.gxf5 Kf6 38.Ke1 g4 39.Ke2 Kg5 40.b3 Kf6 41.Kf1 a5 42.Kf2 Be8 43.a3 b4 44.axb4 axb4 45.Kg2 Bd7 46.Kf2 Be8 47.Kg2 
  =/+  (-0.49)   Depth: 24/56   00:00:21  86937kN
34...Bd7 35.Kc2 Kf7 36.Kd2 f5 37.gxf5 Kf6 38.Ke1 g4 39.Ke2 Kg5 40.b3 Kf6 41.Kf1 a5 42.Kf2 Be8 43.a3 b4 44.axb4 axb4 45.Kg2 Bd7 46.Kf2 Be8 47.Kg2 
  =/+  (-0.49)   Depth: 25/56   00:00:25  102mN
34...Bd7 35.Kc2 
  =/+  (-0.42 --)   Depth: 26/56   00:00:30  126mN
34...Bd7 35.Kc1 Kf7 36.Kd2 f5 37.gxf5 Kf6 38.Ke1 g4 39.Ke2 Kg5 40.b3 Kf6 41.Kf1 a5 42.Kf2 Be8 43.a3 b4 44.axb4 axb4 45.Kg2 Bd7 46.Kf2 Be8 47.Kg2 
  =/+  (-0.49)   Depth: 26/60   00:01:15  324mN
34...Bd7 
  =/+  (-0.55 ++)   Depth: 27/60   00:01:28  386mN
34...Bd7 35.Kc1 
  =/+  (-0.42 --)   Depth: 27/64   00:01:39  430mN
34...Bd7 35.Kc1 Kf7 36.Kd2 f5 37.gxf5 Kf6 38.b4 g4 39.Ke2 Kg5 40.a3 Kxh6 41.f6 Be6 42.Bxc6 Bc4+ 43.Ke1 Kg6 44.Be4+ Kxf6 45.c6 Ke6 46.Bxh7 g3 47.Be4 Kd6 48.d5 Kc7 49.Bg2 Bd3 50.Kd2 Bf5 51.Bf3 Bh3 52.Ke2 Kd6 53.Ke1 Kc7 54.Ke2 Kd6 
  =/+  (-0.59)   Depth: 27/74   00:02:40  686mN
34...Bd7 35.Kc1 Kf7 36.Kd2 f5 37.gxf5 Kf6 38.b4 g4 39.Ke2 Kg5 40.a3 Kxh6 41.f6 Be6 42.Bxc6 Bc4+ 43.Ke1 Kg6 44.Be4+ Kxf6 45.c6 Ke6 46.Bxh7 g3 47.Be4 Kd6 48.d5 Kc7 49.Bg2 Bd3 50.Kd2 Bf5 51.Bf3 Bh3 52.Ke2 Kd6 53.Ke1 Kc7 54.Ke2 Kd6 
  =/+  (-0.59)   Depth: 28/74   00:03:07  801mN
34...Bd7 35.Kc1 Kf7 36.Kd2 f5 37.gxf5 Kf6 38.b4 g4 39.Ke2 Kg5 40.a3 Kxh6 41.f6 Be6 42.Bxc6 Bc4+ 43.Ke1 Kg6 44.Be4+ Kxf6 45.c6 Ke6 46.Bxh7 g3 47.Be4 Kd6 48.d5 Kc7 49.Bg2 Bd3 50.Kd2 Bf5 51.Bf3 Bh3 52.Ke2 Kd6 53.Ke1 Kc7 54.Ke2 Kd6 
  =/+  (-0.59)   Depth: 29/74   00:04:15  1091mN
34...Bd7 35.Kc1 
  =/+  (-0.53 --)   Depth: 30/74   00:04:45  1232mN

(E. Yavuz, Istanbul 08.09.2012)

[zullil]

Critter-1.6a:

Code: Select all

32/78  37:27   25769M  11467K  +1.01 Bd7 Kc1 Kf7 Kd2 f5 gxf5 Kf6 b4 g4 Ke2 Kg5 a3 Kxh6 f6 Be6 Bxc6 Bc4+ Ke1 Kg6 Be4+ Kxf6 c6 Ke6 Bxh7 g3 Be4 Ke7 Bg2 Kd6 d5 Bd3 Bf3 Kc7 Kd2 Bb1 Ke2 Bf5 Kf1 Bh3+ Ke2 Kd6 Ke1 Ke5 Ke2 Kd6

[Ajedrecista]

Hello!

Thanks for your interest. I briefly analyzed your suggested mainlines with Houdini and the position still looks drawish for me. It is maybe a draw, after all.

@Eren: I took a look into ImmortalChess forum to see that Rampage is a private engine:

Rampage Rampage v2.75.64 (Private)

In other thread I see that Stockfish and IvanHoe ideas are used in Rampage:

Rampage 0.52.2 x64 (Private)

I see that your mainline at depth 29/74 is a little wrong according to Houdini: the second time that white plays Kd2, Houdini evaluates it as a blunder (it suggests Bh1 as a better move), giving ..., Bf5 as winning for black; then, ..., Bh3 (by black) is also evaluated as other blunder because it gives away the winning advantage, that could be maintained with ..., Bg4. So, the author should take a glance to the evaluation function IMHO.

@Louis: It is good to see Critter here! But disgracefully the end of the suggested mainline is only evaluated around -0.35 or -0.4 by Houdini on my slow computer. Furthermore, it seems that black can not advance in a winning plan.

Overall I am very satisfied with my play but the position looks drawn in my patzer eyes.

Regards from Spain.

Ajedrecista.