Is this position a win for white?

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Uri Blass
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Location: Tel-Aviv Israel

Is this position a win for white?

Post by Uri Blass » Sat Jan 27, 2018 7:40 am

[D]2k5/2p5/1q1p4/pPpPp1pp/N1P1Pp2/P4PbP/KQ4P1/8 w - - 0 1

I am not sure about it.

I am sure Nxb6 is a draw but I am not sure if white can win the game by winning the pawn a5 black may also sacrifice it by a4 in some cases.

Can you modify it to a better test position when it is clear that white is winning after not capturing b6 but the difference in score between the best 2 moves is high even after a long search?

lech
Posts: 1052
Joined: Sun Feb 14, 2010 9:02 pm

Re: Is this position a win for white?

Post by lech » Sun Jan 28, 2018 10:42 am

I think that it is not that important: win or draw?
The main question is: how to avoid Nxb6 ? :)
Maybe, I can't be friendly, but let me be useful.

MikeGL
Posts: 898
Joined: Thu Sep 01, 2011 12:49 pm

Re: Is this position a win for white?

Post by MikeGL » Sun Jan 28, 2018 10:59 am

I also tried, and it seems h4 instead of Nxb6 could win for white.

MikeGL
Posts: 898
Joined: Thu Sep 01, 2011 12:49 pm

Re: Is this position a win for white?

Post by MikeGL » Sun Jan 28, 2018 11:24 am

MikeGL wrote:I also tried, and it seems h4 instead of Nxb6 could win for white.
Sorry, I tried again. Defence of black remains the same and I can not find the win.

lech
Posts: 1052
Joined: Sun Feb 14, 2010 9:02 pm

Re: Is this position a win for white?

Post by lech » Sun Jan 28, 2018 2:10 pm

I am still working at the new version of Sting (> 3 months) and now the problem is solved in such a way:
[d]2k5/2p5/1q1p4/pPpPp1pp/N1P1Pp2/P4PbP/KQ4P1/8 w - - avoid Nxb6+;

Code: Select all

info depth 31 multipv 1 score cp 113 nodes 31175085 nps 762898 time 40864 pv a4b6 c7b6 b2c2 h5h4 a2b3 c8d7 b3c3 d7e7 c3d3 e7e8 c2e2 e8e7 e2f1 e7f6 d3c3 f6e7 f1e2 e7d7 e2d2 d7e7 c3d3 e7d7 d2c3 d7e7 c3b2 e7d7 b2d2 d7e7 d2e2 e7d7 e2d1 g3f2
info depth 32
info currmove a4b6 currmovenumber 1
info currmove h3h4 currmovenumber 2
info currmove a2b3 currmovenumber 3
info currmove b2c2 currmovenumber 4
info currmove a4c3 currmovenumber 5
info currmove b2b3 currmovenumber 6
info currmove b2c3 currmovenumber 7
info currmove b2a1 currmovenumber 8
info currmove b2c1 currmovenumber 9
info currmove b2d2 currmovenumber 10
info depth 32 multipv 1 score cp 121 lowerbound nodes 81691673 nps 747373 time 1
09305 pv b2d2
info currmove b2d2 currmovenumber 1
info depth 32 multipv 1 score cp 129 lowerbound nodes 90095826 nps 748832 time 1
20315 pv b2d2
info currmove b2d2 currmovenumber 1
info depth 32 multipv 1 score cp 141 lowerbound nodes 124219721 nps 744155 time
166927 pv b2d2 b6a7 a2b3 g3h2 a4c3 h2g1 b3a4 g1e3 d2e1 c8d7 c3e2 d7e7 e1a5 a7a5 a4a5 e3d2 a5a4 d2e3 a4b3 e3d4 a3a4 d4e3 a4a5 e3d4 e2d4 c5d4 a5a6 d4d3 a6a7 d3d2 b3c2 h5h4 a7a8q e7d7 c2d2 d7e7 d2e2 e7d7 e2f2
info currmove b2d2 currmovenumber 1
info currmove a4b6 currmovenumber 2
info currmove h3h4 currmovenumber 3
info currmove a4c3 currmovenumber 4
info currmove b2e2 currmovenumber 5
info currmove b2c3 currmovenumber 6
info currmove b2c2 currmovenumber 7
info currmove a2b3 currmovenumber 8
info currmove a2b1 currmovenumber 9
info currmove b2c1 currmovenumber 10
info currmove b2b3 currmovenumber 11
info currmove b2f2 currmovenumber 12
info currmove b2b4 currmovenumber 13
info currmove b2b1 currmovenumber 14
info currmove b2a1 currmovenumber 15
info currmove b2d4 currmovenumber 16
info currmove a2a1 currmovenumber 17
info currmove a4c5 currmovenumber 18
info currmove b2e5 currmovenumber 19
info depth 32 multipv 1 score cp 137 nodes 296897255 nps 744786 time 398634 pv b2d2 b6a7 a2b3 g3h2 a4c3 h2g1 b3a4 g1e3 d2e1 e3d4 c3e2 c8b7 e1a5 a7b6 a5e1 b6a7 a4b3 b7b6 a3a4 a7a5 e1a5 b6a5 e2c1 d4e3 c1d3 e3d4 b3a3 d4e3 d3e1 e3d4 a3b3 a5b6 e1c2 b6a5 c2a3 a5b6
info depth 33
info currmove b2d2 currmovenumber 1
But I also doubt that it has sense to wait for a clear win. :wink:
Maybe, I can't be friendly, but let me be useful.

BeyondCritics
Posts: 346
Joined: Sat May 05, 2012 12:48 pm
Location: Bergheim

Re: Is this position a win for white?

Post by BeyondCritics » Sun Jan 28, 2018 9:58 pm

Uri Blass wrote:[D]2k5/2p5/1q1p4/pPpPp1pp/N1P1Pp2/P4PbP/KQ4P1/8 w - - 0 1

I am not sure about it.

I am sure Nxb6 is a draw but I am not sure if white can win the game by winning the pawn a5 black may also sacrifice it by a4 in some cases.

Can you modify it to a better test position when it is clear that white is winning after not capturing b6 but the difference in score between the best 2 moves is high even after a long search?
So you can't elicit the winning line, or what is the problem here?
You neither want to allow black to activate his bishop, nor do you want to allow black to activate his queen with a4 and Qa5.
Simply Qd2, Kb3, Nb2, Ka4, Nd3-c1-b3xa5 should do the trick.

zullil
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Location: PA USA
Full name: Louis Zulli

Re: Is this position a win for white?

Post by zullil » Sun Jan 28, 2018 10:32 pm

BeyondCritics wrote: So you can't elicit the winning line, or what is the problem here?
You neither want to allow black to activate his bishop, nor do you want to allow black to activate his queen with a4 and Qa5.
Simply Qd2, Kb3, Nb2, Ka4, Nd3-c1-b3xa5 should do the trick.
Black gets to move too. :wink:

kgburcham
Posts: 2016
Joined: Sun Feb 17, 2008 3:19 pm

Re: Is this position a win for white?

Post by kgburcham » Sun Jan 28, 2018 11:35 pm

Simply Qd2, Kb3, Nb2, Ka4, Nd3-c1-b3xa5 should do the trick.

1. Qd2 Qa7 2. Kb3 Qa8 3. Nb2 Kb7 4. Ka4 Bh2 5. Nd3 Bg1
6. Nc1 Be3 7. Qc3 Bxc1 8. Qxc1 g4

[D] q7/1kp5/3p4/pPpPp2p/K1P1Ppp1/P4P1P/6P1/2Q5 w - -


43/86 2:23 0.00 9.fxg4 hxg4 10.hxg4 Qg8

did I make a mistake?

kgburcham
no chess program was born totally from one mind. all chess programs have many ideas from many minds.

BeyondCritics
Posts: 346
Joined: Sat May 05, 2012 12:48 pm
Location: Bergheim

Re: Is this position a win for white?

Post by BeyondCritics » Sun Jan 28, 2018 11:54 pm

kgburcham wrote:
Simply Qd2, Kb3, Nb2, Ka4, Nd3-c1-b3xa5 should do the trick.

1. Qd2 Qa7 2. Kb3 Qa8 3. Nb2 Kb7 4. Ka4 Bh2 5. Nd3 Bg1
6. Nc1 Be3 7. Qc3 Bxc1 8. Qxc1 g4

[D] q7/1kp5/3p4/pPpPp2p/K1P1Ppp1/P4P1P/6P1/2Q5 w - -


43/86 2:23 0.00 9.fxg4 hxg4 10.hxg4 Qg8

did I make a mistake?

kgburcham
Your mistake is, that you think you are a computer.
This line was an expression of an _idea_, the way normal clubplayers think.
Last edited by BeyondCritics on Sun Jan 28, 2018 11:58 pm, edited 1 time in total.

BeyondCritics
Posts: 346
Joined: Sat May 05, 2012 12:48 pm
Location: Bergheim

Re: Is this position a win for white?

Post by BeyondCritics » Sun Jan 28, 2018 11:54 pm

zullil wrote:
BeyondCritics wrote: So you can't elicit the winning line, or what is the problem here?
You neither want to allow black to activate his bishop, nor do you want to allow black to activate his queen with a4 and Qa5.
Simply Qd2, Kb3, Nb2, Ka4, Nd3-c1-b3xa5 should do the trick.
Black gets to move too. :wink:
You have strong hardware, so whats the winning line anyway?

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