How Many Games of Chess?

[Lefty]

>This is tangentially related to crypto.  I've been reading A.K. Dewdney's
>I was glancing through the chapters on complexity,
>computabilty, and minimax trees, and I got to wondering something:  how
>many possible games of chess are there?  I know that it has to be a finite
>number, but I'm not sure how to go about finding this number.  Any
>pointers would be appreciated.

It doesn't seem to me that this _can_ be readily calculated in any
reasonable amount of time.  It's not a simple (realtively) combinatorial
problem: the configuration of the board at any given point limits the legal
moves in an extremely nontrivial way.

I believe I can get you as far as the second move, though: I make it to be
twenty-one possible openings and twenty-one responses.

--
Lefty (lefty at apple.com)
C:.M:.C:., D:.O:.D:.