Author: Robert Hyatt
Date: 07:46:49 05/07/03
Go up one level in this thread
On May 06, 2003 at 11:14:19, José Carlos wrote: >On May 06, 2003 at 08:55:07, Robert Hyatt wrote: > >>On May 06, 2003 at 07:05:02, Jarkko Pesonen wrote: >> >>>Crafty 19.3 ends up in this position >>> white black >>> 1 d5 e5 >>> 2 c6+ bxc6 >>> 3 bxc6+ Kc8 >>> 4 d6 e4 >>> 5 Kd4 h5 >>> 6 g4 hxg4 >>> 7 hxg4 f4 >>> 8 Kxe4 ... >>> >>>[D]2k5/8/2PP4/6p1/4KpP1/8/8/8 b >>> >>> 21-> 1:40 6.47 1. ... Kd8 2. Kd4 Kc8 3. Kd3 Kd8 4. >>> Ke4 Kc8 5. Kf3 Kd8 6. Kf2 Kc8 7. Ke2 >>> Kd8 8. Kd3 Kc8 9. Kc3 Kd8 10. Kd2 Kc8 >>> 11. Ke1 f3 >>> >>>Seems that crafty isn't doing any progress and score is totally wrong(seems to >>>be draw). >>> >>>Is there an easy way to fix this? >>>Or is this some kind off odd situation that is so rare that it is not >>>worth fixing? >>> >>>Jarkko >> >> >>That can be fixed. It is the classic problem of two connected passed pawns >>being valued too high in a king and pawn ending. If they were separated, >>white would win easily. But together, they can be stopped. I will look >>at this and fix it. The code is already there, it just has a hole that I >>apparently overlooked. > > These kind of position is very tricky. In some cases, white can forget about >the black pawns and go with the king to help his pawns. AFAIK it can only be >safely solved by search. > > José C. I agree. But the way it is done, the error rate is higher than it should be, I've explained why previously. Two connected passers are not what you want in a king and pawn ending if your opponent has two passers that are separated. I have code to do this right, but it has a hole in it that I had overlooked...
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.