Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: 10^120 is the answer regis!

Author: Vincent Vega

Date: 18:42:55 12/23/00

Go up one level in this thread


On December 23, 2000 at 17:56:23, Robert Hyatt wrote:

>On December 23, 2000 at 14:41:37, Uri Blass wrote:
>
>>On December 23, 2000 at 12:44:52, Robert Hyatt wrote:
>>
>>>On December 23, 2000 at 12:25:18, Uri Blass wrote:
>>>
>>>>On December 23, 2000 at 09:01:29, Joshua Lee wrote:
>>>>
>>>>>this is over a google and even if your program could search at 5 trillion nodes
>>>>>per second it wouldn't solve chess in your lifetime.
>>>>>
>>>>> 64^64 is one number that comes to mind  3.9402006196394479212279040100144e+115
>>>>
>>>>The number of leagl positions is clearly smaller than 64^64.
>>>>
>>>>I do not understand why do you think about 64^64.
>>>>
>>>>Uri
>>>
>>>
>>>I still think 10^120 is a reasonable estimate, because a position  is not just
>>>made up of the pieces on the board.
>>
>>In order to find if chess is a win for one side or a draw you need only
>>tablebases for all the positions in the board when the position is made only of
>>the pieces on the board.
>>
>
>
>That isn't true.  If you do that, you will draw won positions, because
>you will follow a path that is a mate in N, but it repeats the position
>for the third time before you get to move N.  Ditto for 50 move draws
>on deep mates.  To do this _right_ the history has to be included.
>

This is clearly wrong.  Chess has a well defined starting position, so you don't
need to be able to figure out the best move in every possible position with its
associated history to find out if chess is 1-0, 0-1, or 1/2-1/2.

Adding 50-move and 3-fold repetition conditions has no effect whatsoever on
whether computer will be able to play perfect chess.  If you play the game
perfectly from the beginning, and there is a win for one side, there won't ever
be any repetitions of positions.  And if you follow the algorithm that chooses
the next move by finding the minimum distance to resetting the 50-move counter
among all moves that lower the distance to mate, you won't need to know the game
history at all.

I don't find figuring out when computer will be able to play perfectly from any
possible position nearly as important as knowing when a computer will play
perfectly from the only position that really counts - starting position.



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.