Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Endgame Analysis

Author: Steffen Jakob

Date: 03:30:34 11/04/01

Go up one level in this thread


On November 03, 2001 at 19:21:09, Robert Hyatt wrote:

>On November 03, 2001 at 07:07:55, Colin Frayn wrote:
>
>>OK, this is probably the stupidest post you'll ever read on CCC.
>>
>>Take the following completely trivial endgame position;
>>
>>[D]8/8/8/3P3k/K3p3/8/8/8 w - -
>>
>>It's obvious to anyone who's ever vaguely heard of chess that this is a draw.
>>
>>However, if one carefully codes in the promotion squares algorithm, it's clear
>>that the white king can catch the black pawn, but the black king cannot catch
>>the white pawn (as it has the move).  Now, the problem is that (obviously) if
>>the white king attempts to catch the black pawn then of course the black king
>>moves one square closer to the white pawn, and can now catch it.
>>
>>So, statically, how do you say that this is obviously a draw?  Bear in mind that
>>you have to be careful about similar positions where the extra square advantage
>>given by the side with a passed pawn having the move might make all the
>>difference.
>>
>>This has got to be easy, right?
>>
>>Incidentally, just so that I cover my back and prove that I'm not being totally
>>stupid, Crafty v18.11 static evaluation scores this as +6.20 for white.
>>
>>Cheers,
>>Col
>
>
>Try it with a simple search:
>
>                1     0.02   0.73   1. d6
>                1->   0.02   0.73   1. d6
>                2     0.02     --   1. d6
>                2     0.02   0.00   1. d6 e3
>                2->   0.03   0.00   1. d6 e3
>                3     0.03   0.20   1. d6 e3 2. Kb5
>                3->   0.04   0.20   1. d6 e3 2. Kb5
>                4     0.04   0.00   1. d6 e3 2. Kb5 e2 3. d7 e1=Q 4. d8=Q
>                4->   0.04   0.00   1. d6 e3 2. Kb5 e2 3. d7 e1=Q 4. d8=Q
>                5     0.05   0.00   1. d6 e3 2. Kb5 e2 3. d7 e1=Q 4. d8=Q
>
>
>The point is that once a move is made, the die is cast.  And the evaluation
>becomes correct...  The original position has two plans...  which give a
>static evaluation fits...  fortunately that is why we have a search to help
>the evaluation. :)  One move resolves the position..

Yes, but in other cases the position above will be a leaf node and might lead
you to a totally wrong PV.

Greetings,
Steffen.



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.