Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Correction, How Many programs besides Crafty can find it?

Author: Jorge Pichard

Date: 01:10:50 04/12/03

Go up one level in this thread


On April 12, 2003 at 04:09:45, Jorge Pichard wrote:

>On April 12, 2003 at 01:40:31, Robert Hyatt wrote:
>
>>On April 11, 2003 at 18:26:32, Jorge Pichard wrote:
>>
>>>Which Pawn should White push in order to win, please provide Analylis.
>>>
>>>[D]8/8/3P3P/5r2/2P5/2P4k/8/6K1 w - - 0 1
>>
>>My human eye says c5.  If Rxc5 then d7 and Rd5 is met by h7 and black is
>>pretty well hosed...
>>
>>The key is getting the rook to a square where it has to prevent
>>one pawn from queening from behind, because it can't stop both from
>>there, it needs to be on the first rank.
>>
>>Hence c5 to lure it away.
>>
>>cute position since Rc5 is not playable and anything else has trouble with
>>c6.
>>
>>I let crafty grind on this after I looked at it and sure enough, at depth
>>17 it fails high on c5.  Takes 5 minutes to find it however, on my dual 2.8.
>>
>>Can you show me the Analysis on your dual 2.8 Ghz.
>
>Yes c5! is the only winning move, but not too many programs can see this, not
>even after 5 Minutes.
>
>1. c5 Kg3 2. h7 Rf8 3. c6 Ra8 4. Kf1 Kf3 5. Ke1 Ke3 6. Kd1 Kd3 7. Kc1 Kxc3 8.
>Kd1 Kd3 9. Ke1 Ke3 10. Kf1 Kf3 11. Kg1 Kg3 12. h8=Q Rxh8 13. c7 it must be this
>pawn, since the b8 square is a vital one for Black's defense Ra8 14. Kf1 Kf3 15.
>Ke1 Ke3 16. Kd1 Kd3 17. Kc1 Kc3 18. Kb1 now there is no check on b8, so White
>wins, There will follow 19. d7 and the birth of a queen.
>
>
>If h7?? this is how Black King will stop it and mop the White pawns:
>1. h7 Rf8 2. c5 Kg4 3. c6 Kf5 4. d7 Ke6 etc...
>
>
>If d7?? this is how Black King will stop it and mop the White pawns:
>1. d7 Rf8 2. c5 Kg3 3. c6 Ra8 4. Kf1 Kf3 5. Ke1 Ke3 6. Kd1 Kd3 7. Kc1 Kxc3 8.
>Kb1 Rb8+ 9. Ka2 Ra8+ 10. Kb1 Rb8+ Draw
>
>
>>>
>>>-------------------------------------------------------------------------------
>>>This is another position of Reciprocal Zugzwang: If White is to play, then he
>>>can only draw, but if Black is to play, he loses. In other words, any move by
>>>either side weakens his position to the extend of worsening the result of the
>>>game!
>>>
>>>[D]1R4br/8/8/8/8/4K3/k5P1/8 w - - 0 1
>>
>>Crafty says g3 is a dead draw.



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.