Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!cs225ju
From: cs225ju@ux1.cso.uiuc.edu) (Matt Pavlik ;)
Newsgroups: comp.ai
Subject: Re: Chess question
Message-ID: <1991Mar18.184332.12001@ux1.cso.uiuc.edu>
Date: 18 Mar 91 18:43:32 GMT
References: <velasco.668928518@beowulf> <1991Mar18.045610.2977@ux1.cso.uiuc.edu> <18585@milton.u.washington.edu>
Organization: University of Illinois at Urbana
Lines: 22

In article <18585@milton.u.washington.edu> forbis@milton.u.washington.edu (Gary Forbis) writes:

>In fact, not every game must be considered but merely the ones whose positions
>are forced mate for one side or the other or are unavoidably a draw.  Would
>every position be encountered in the course of playing what were considered
>optimal games using a database of positions encountered within such games
>which are forced mate?

I got that number from a AI book and a few other books also had that number,
Im certainly no expert, as I havent even had an AI course yet and I agree
with what you say, but I think the problem is:
  
In any game it's always possible to end up in any given "legal" board
position.  In order to make sure this position doesn't lead to some other
outcome, all possibilities must be checked.  ( I think the original question
asked if white should always be able to win. )  
How does the computer know what positions are going to lead to forced
mate if it hasnt already checked all the posibilities?

Does this make any sense?

Matt