The two bishops are letting me down

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Lyudmil Tsvetkov
Posts: 6052
Joined: Tue Jun 12, 2012 12:41 pm

The two bishops are letting me down

Post by Lyudmil Tsvetkov »

Hi.
Once I learned how to post diagrams, I am eager to post another one, and there is no stopping now.

[d]8/1pn2pkp/p1p1n1p1/8/2P5/3BBP2/PP3PKP/8 w 0 1

I already posted something relating to this: http://talkchess.com/forum/viewtopic.ph ... 01&t=46755

It would be interesting to know how do you (and your engines, of course) evaluate the above position. Are there any engines that actually see black in advantage? (and weak and very weak engines would not count here, as my guess is that among those there will be many displaying the correct evaluation :))

My take on that: white has a pair of bishops, there are pawns on both sides, better control of center, and even its mobility seems to be better. And the two knights are even usually weaker than a bishop and a knight. There are no blocked pawns that would favour the knights. So, at first glance, white should be much better. However, the only weakness in white's pawn structure, the double f pawns, is so significant and long-lasting, that, for me, the evaluation should definitely be in black's favour. There is nothing the bishops could do to help in undoubling the f pawns, as there are no friendly pawns able to assist in the task.

Are there any engines actually seeing black in advantage?

Best regards,
Lyudmil
User avatar
Ajedrecista
Posts: 2230
Joined: Wed Jul 13, 2011 9:04 pm
Location: Madrid, Spain.

Re: The two bishops are letting me down.

Post by Ajedrecista »

Hello Lyudmil:
Lyudmil Tsvetkov wrote:Hi.
Once I learned how to post diagrams, I am eager to post another one, and there is no stopping now.

[d]8/1pn2pkp/p1p1n1p1/8/2P5/3BBP2/PP3PKP/8 w 0 1

I already posted something relating to this: http://talkchess.com/forum/viewtopic.ph ... 01&t=46755

It would be interesting to know how do you (and your engines, of course) evaluate the above position. Are there any engines that actually see black in advantage? (and weak and very weak engines would not count here, as my guess is that among those there will be many displaying the correct evaluation :))

My take on that: white has a pair of bishops, there are pawns on both sides, better control of center, and even its mobility seems to be better. And the two knights are even usually weaker than a bishop and a knight. There are no blocked pawns that would favour the knights. So, at first glance, white should be much better. However, the only weakness in white's pawn structure, the double f pawns, is so significant and long-lasting, that, for me, the evaluation should definitely be in black's favour. There is nothing the bishops could do to help in undoubling the f pawns, as there are no friendly pawns able to assist in the task.

Are there any engines actually seeing black in advantage?

Best regards,
Lyudmil
Analysis by Critter 1.4 w32 (using four cores) in an Intel i5-760 (2.8 GHz), with 64 MB of hash, running in console mode:

Code: Select all

Critter v1.4 32-bit, by Richard Vida
position fen 8/1pn2pkp/p1p1n1p1/8/2P5/3BBP2/PP3PKP/8 w 0 1
go infinite
info string Opening book "book.cbk" not found
info string GTB Init FAILED
info string Using 4 thread(s), 64 MB hash
 2/ 2  00:00        84    1909  +0.14 Bc2 Ne8
 3/ 4  00:00       297    6187  +0.10 Bc2 Ne8 h4 Nd6
 4/ 5  00:00       492    9840  +0.10 Bc2 Ne8 h4 Nd6
 5/ 6  00:00      1042   19660  +0.01 Bc2 Ne8 h4 Nd6 b3
 5/ 6  00:00      2629   45327  +0.01 b4 Ne8 b5 Nd6 bxc6 bxc6
 5/ 6  00:00      2971   47919  +0.03 h4 Ne8 Bb1 Nd6 b3
 6/ 7  00:00      3425   52692  +0.07 h4 Ne8 Bb1 Nd6 b3 c5
 7/ 8  00:00     10416  148800  +0.00 h4 Ne8 Kg3 Nf6 Bb1 Nh5+ Kg4 Nf6+ Kh3
 8/ 9  00:00     12978  170763  +0.00 h4 Ne8 Kg3 Nf6 Bb1 c5 Be4 Nh5+ Kg4 Nf6+ Kg3
 9/13  00:00     40666  446879  -0.07 b4 Ne8 a4 Kf6 a5 Ke5 Kg3 Nd6 f4+ Kf6
10/14  00:00     73079  702682  -0.09 b4 Ne8 Kg3 Kf6 Bd2 Nd6 Bc3+ Ke7 c5 Nb5 Be5
11/15  00:00    194705 1390750  -0.11 b4 Ne8 h3 Kf6 f4 Nd6 Kf3 Nf5 Bb6 h5 Ke4 Nd6+ Ke3
12/16  00:00    340479 1881099  -0.05 b4 Ne8 f4 f5 Kf3 Nd6 Bc1 c5 Bb2+ Kf7 Be5 Ne4
13/16  00:00    388522 1972192  -0.11 b4 Ne8 f4 f5 Kf3 Nd6 a4 Kf7 c5 Ne8 b5 axb5 axb5 Nf6 bxc6 bxc6
14/17  00:00    641341 2565364  -0.11 b4 Ne8 f4 f5 Kf3 Nd6 a4 Kf7 c5 Ne8 b5 axb5 axb5 Nf6 bxc6 bxc6
15/23  00:00   2096423 4151332  -0.12 b4 b6 Be4 c5 h4 Kf6 Kg3 Ne8 bxc5 bxc5 Bb7a5 Bd2 Nd6 Bd5 Nf5+ Kh3
16/25  00:00   4138848 4903848  -0.12 b4 b6 a4 c5 bxc5 bxc5 Be4 f5 Bb7 Kf6 Kg3 Nd4 h4 Kf7 Bd2 Ke6 a5 Kf7
17/25  00:01   5935443 5188324  -0.15 b4 b6 a4 c5 bxc5 bxc5 Be4 Kf6 Bb7 Ke7 h4 Kd7 Bd2 Nd4 Kg3 f5 a5 Ke6 Bc8+ Kf7
17/27  00:01   6523181 5193615  -0.07 f4 f5 h4 Kf6 Be2 c5 h5 Nd4 Bd1 Nce6 Kg3 b6 hxg6 hxg6 Bd2 Ng7 Kh4 Ne8
18/27  00:01   8248323 5412285  -0.10 f4 f5 h4 Kf6 Be2 c5 h5 Nd4 Bd1 Nce6 Kg3 b6 hxg6 hxg6 Bd2 Ng7 Bc1 Nh5+ Kh4
19/36  00:02  14403420 5805489  -0.09 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 a3 Kf6 Kf3 b6 Ke2 N8g7 b4 Nh5 Kf3 a5 bxc5 bxc5 Bd2 Nd4+ Ke3
20/36  00:03  22470973 6083100  -0.08 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 Kf3 Kf7 Bf1 Nd6 Bd3 Kf6 Ke2 b6 Kf3 Ne8 b4 Ke7 a3 Kd6 Ke2 Nf6 f3 Nd4+ Bxd4 cxd4
21/36  00:06  35457340 5484507  -0.07 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 Kf3 Kf7 Bf1 Nd6 Bd3 Kf6 b3 Ke7 Ke2 b6 Bc1 Ne8 Ke3 Nf6 f3 Nd4 Bf1
22/36  00:10  58286145 5319049  -0.07 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 Kf3 Kf7 Bf1 Nd6 Bd3 Kf6 b3 Ke7 Ke2 b6 Bc1 Ne8 Ke3 Nf6 f3 Nd4 Bf1
23/39  00:18 109169998 5971120  -0.10 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 Kf3 Kf7 a3 Ke7 Bd2 Nf6 Bc3 Nd4+ Bxd4 cxd4 Bf1 Kd6 Ke2 Nh5 Kd3 Nxf4+ Kxd4 Ne6+ Ke3 Nc5
24/45  00:41 272470751 6581737  -0.12 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 Kf3 Kf7 a3 Ke7 Bd2 Nf6 Bc3 Nd4+ Bxd4 cxd4 Bf1 Kd6 Ke2 Nh5 Kd3 Nxf4+ Kxd4 Ne6+ Ke3 Ke5 b4
25/46  01:28 609076687 6861985  -0.12 f4 f5 h4 c5 h5 Ne8 hxg6 hxg6 Kf3 Kf7 Bd2 Nf6 Bc3 b6 b4 cxb4 Bxb4 Nc5 Bc2 a5 Bxc5 bxc5 Ke2 Ke6 f3 Ne8 Ba4 Nd6
26/46  03:02 1260349181 6904244  -0.04 f4 Kf6 Kf3 Ne8 b4 Nd6 c5 Nf5 Bc4 Ke7 Bd2 Nh4+ Ke4 Kd7 a3 Ke7 h3 f6 Bf1 Nc7 Bc4 f5+ Ke3 Nd5+ Bxd5 cxd5 Bc3 Ng2+ Kf3
27/46  03:54 1641650882 6998434  -0.06 f4 Kf6 Kf3 Ne8 b4 Nd6 c5 Nf5 Bc4 Ke7 Bd2 Nh4+ Ke4 Kd7 Ke3 h6 Ke4 a5 a3 f5+ Ke3 a4 Bf1 Nc7 Bc4 Nb5 Bc1 Ng2+ Kd3
28/50  07:13 3061155265 7059306  -0.07 f4 Kf6 Kf3 Ne8 b4 Nd6 c5 Nf5 Bc4 Ke7 Ke4 Nxe3 fxe3 f5+ Kd3 a5 a3 a4 Bxe6 Kxe6 Kc4 Ke7 Kc3 Kd7 Kd3 h6 e4 fxe4+ Kxe4
stop
bestmove f4 ponder Kf6

time: 535218 nodes: 3819300864 evals: 2107344028 knps: 7135
phash: 71.11% evalcache: 22.19% lazy: 27.00% eg_recog: 100980614
splits: 293660
Critter 1.4 evaluate this endgame (or late middlegame or whatever it is) as a draw (near zero evals) from the very first moment.

Regards from Spain.

Ajedrecista.
Lyudmil Tsvetkov
Posts: 6052
Joined: Tue Jun 12, 2012 12:41 pm

Re: The two bishops are letting me down.

Post by Lyudmil Tsvetkov »

Hi Jesus.
If I were Critter, on f4 I would consider playing f5 as my only choice.
But unfortunately I am not Critter :evil:
User avatar
velmarin
Posts: 1600
Joined: Mon Feb 21, 2011 9:48 am

Re: The two bishops are letting me down.

Post by velmarin »

My engines say 0.00 and -0.10 to touch,

The difference is simply the value in the pair of bishops.

no speculation.