Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Easy draw

Author: Robert Hyatt

Date: 11:30:22 01/02/02

Go up one level in this thread


On January 02, 2002 at 11:43:55, Benny Antonsson wrote:

>On January 02, 2002 at 11:28:12, Robert Hyatt wrote:
>
>>On January 02, 2002 at 10:12:29, Benny Antonsson wrote:
>>
>>>This is an easy draw, but how do one make your program see it ?
>>>Do you make special cases in the static evaluator or do you rely on EGTBs ?
>>>
>>>[D] 8/8/p4k2/1bKR1r2/8/8/8/8 w - - 0 60
>>>
>>>White king reaches the a1 square after Rxf5+ Kxf5 and black cannot win.
>>
>>
>>You need special knowledge in the endgame evaluation code.  It is not
>>difficult at all:
>>
>>         nss  depth   time  score   variation (1)
>>                1     0.00   0.00   1. Rxf5+ Kxf5 2. Kd6
>>                1->   0.00   0.00   1. Rxf5+ Kxf5 2. Kd6
>>                2     0.00   0.00   1. Rxf5+ Kxf5 2. Kd5 Bf1
>>                2->   0.00   0.00   1. Rxf5+ Kxf5 2. Kd5 Bf1
>>                3     0.00   0.00   1. Rxf5+ Kxf5 2. Kd5 Bf1 3. Kd6
>>                3->   0.00   0.00   1. Rxf5+ Kxf5 2. Kd5 Bf1 3. Kd6
>>                4     0.00   0.00   1. Rxf5+ Kxf5 2. Kd5 Bf1 3. Kc5 Ke4
>>                4->   0.00   0.00   1. Rxf5+ Kxf5 2. Kd5 Bf1 3. Kc5 Ke4
>>
>>
>>That is not an EGTB score, it is the result of the evaluation knowing
>>that bishop + wrong rook pawn can't win if the opposing king can reach
>>the queening square first.
>
>So... I have to implement a kind of "racing"-function ? ~ Which king reacher
>(controls) the a1-square first. ?


Basically, but it can be a fast static computation rather than some sort
of tree search.



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.