From: wcs@anchor.ho.att.com (bill.stewart@pleasantonca.ncr.com +1-510-484-6204)
Date: Tue, 5 Apr 94 18:57:08 PDT
To: cypherpunks@toad.com
Subject: Re: How Many Games of Chess: Exact answer given!
Message-ID: <9404060156.AA23324@anchor.ho.att.com>
MIME-Version: 1.0
Content-Type: text/plain


> > The natural conclusion is that the complexity of the problem depends on how
> > much of the game you consider to be the `endgame'.  Thus, the actual number
> > of different chess games: 5
> > 
> >  2) White mates
> >  1) Black resigns
> >  0) Stalemate
> > -1) White resigns
> > -2) Black mates

There are at least 3 others - there's
	- Black/White's clock runs out
	- game completion gets postponed for whatever reason
		and never resumed
		
> i am not sure this is a very reasonable question without any 
> restrictions.  while this answer is humerous, i don't think anybody has 
> addressed the fact that i can move a king back and forth between 3 
> squares infinitely many times.  

You can't - after the board has been in the same position three times,
the rules say it's a stalemate.  This lets you calculate an upper bound 
which somebody did a few days ago.