Re: Transactions: good or bad?

From: Larry Coon <lmcoon_at_nospam_cox.net>
Date: Fri, 20 Jun 2003 21:54:49 -0700
Message-ID: <3EF3E519.304A_at_nospam_cox.net>


Bob Badour wrote:  

> Where is your proof that all chess games halt?

For this I have a comment. For the rest of this argument, I'm staying the hell away.

The rules of chess allow the side to move to CLAIM a draw if either of the following occur:

  1. The same position occcurs for the THIRD time (I saw a mistaken claim that a single repetition caused a draw).
  2. Fifty moves occur without either a pawn being moved or a piece taken.

With these rules taken literally, a chess game can be infinite. Each side can play the same two moves repeatedly, and if neither claims a draw, the game doesn't halt. E.g.:

  1. Nf3 Nc6
  2. Ng1 Nb8
  3. Nf3 Nc6

etc..

If the rules were changed to remove the option -- i.e., change the "may claim" to "shall claim," then a chess game becomes finite, and always halts.

Larry Coon
University of California
larry_at_assist.org
and lmcoon_at_home.com Received on Sat Jun 21 2003 - 06:54:49 CEST

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