Author: Robert Hyatt
Date: 06:49:54 10/14/99
Go up one level in this thread
On October 14, 1999 at 01:01:56, Howard Exner wrote:
>On October 13, 1999 at 21:46:31, Steve Schooler wrote:
>
>>On October 13, 1999 at 21:39:33, Steve Schooler wrote:
>>
>>>On October 13, 1999 at 19:49:58, Jeremiah Penery wrote:
>>>
>>>>On October 13, 1999 at 17:23:14, Howard Exner wrote:
>>>>
>>>>>Here's an example of pawn majority knowledge. A program
>>>>>with pawn majority knowledge of the queen side configuration in this
>>>>>example may well find the winning move Qg6+.
>>>>>
>>>>>4Q3/6pk/2pq4/3p4/1p1P3p/1P1K1P2/1PP3P1/8 b - - bm Qg6;
>>>>>
>>>>>After the exchange of queens will follow the the advance of the black king to
>>>>>the kingside, then exchanges of the kingside pawns, and finally the king can
>>>>>march over to pick up the queenside pawns. Is knowledge that white cannot break
>>>>>through on the queenside essential for solving this? Would any program find Qg6?
>>>>
>>>>I think Qg6 only draws.
>>>>
>>>>Here's a line: 1. ...Qg6 2. Qxg6 Kxg6 3. Ke3 Kf5 4. c3 g5 5. Ke2 Kf4 6. Kf2 g4
>>>>7. fxg4 Kxg4, and this will draw.
>>>>
>>>>Can black improve on this?
>>>>
>>>>Jeremiah
>>>
>>>I suspect that black may win by zugzwang : in above line
>>>
>>>4... Kg5 5. Ke2 Kf4 6. Kf2 g6 7. cxb4 g5 8. Kg1 Kg3 9. Kh1 h3
>>>10. gxh3 Kxh3 and (I think) black wins.
>>
>>In above line, from my previous post, I overlooked 8. b5. I now suspect that
>>White can draw.
>
>This is on the right track, just keep playing it through.
>1... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. c3 Kg5 5. Ke2 Kf4 6. Kf2 g6 7. cxb4
>g5 8. b5 cxb5 9. b4 g4 10. fxg4 Kxg4 11. b3 Kf4 12. Kf1
>
>I guess this position carries a bit of venom for programs.
>
>A. Programs are intimidated by the greater number of pawns for white on the
>queenside, thus the reluctance to exchange Queens. Yet in this similar
>position they may very well play Qg6.
>
>4Q3/6pk/2pq4/3p4/1p1P3p/1P1K1P2/2P3P1/8 b - - id Pos 1 - EXAMPLE.EPD; bm Qg6;
>
>It is different only in that the white pawn on b2 is missing. Both are similar
>in that white cannot break through and force a passer though with the
>extra b2 pawn white has some waiting moves that do not help since no passer
>is available.
>
>B. The waiting move with the king 4 ...Kg5, compelling white to move.
>
>C. The liquidation theme, where after black exchanges the kingside pawns
>the king is so dominant that it can move uncontested to the queenside.
>
>I posted this one about a year ago but no one posted that their program found
>Qg6 back then.
that was then, this is now. here is current crafty output:
nss depth time score variation (1)
1 0.00 -0.24 1. ... c5 2. dxc5 Qxc5
1 0.04 -0.21 1. ... g5
1-> 0.05 -0.21 1. ... g5
2 0.05 -0.55 1. ... g5 2. Qh5+ Qh6
2 0.05 ++ 1. ... Qg6+!!
2 0.05 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5
2-> 0.05 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5
3 0.05 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5
4. Ke3
3-> 0.06 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5
4. Ke3
4 0.10 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5
4. Ke3 g6
4-> 0.10 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5
4. Ke3 g6
5 0.11 0.13 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kd3
5-> 0.12 0.13 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kd3
6 0.14 0.19 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kd3 g5
6-> 0.16 0.19 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kd3 g5
7 0.37 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. c4 bxc3
4. Kxc3 Kf5 5. Kb4 Ke6 6. Kc5 Kd7
7-> 0.51 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. c4 bxc3
4. Kxc3 Kf5 5. Kb4 Ke6 6. Kc5 Kd7
8 0.66 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g6 6. Ke2 g5
8-> 0.83 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g6 6. Ke2 g5
9 1.06 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7.
Kf1
9-> 1.22 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7.
Kf1
10 1.76 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7.
Kf1 Kf4
10-> 2.15 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7.
Kf1 Kf4
11 2.96 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7.
Kf1 h3 8. gxh3 Kxf3
11-> 3.60 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5
4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7.
Kf1 h3 8. gxh3 Kxf3
~
so at least now it has an inkling that this is good.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.