Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Approximate # of Unique chess positions = (current estimated #)/4

Author: Dann Corbit

Date: 11:32:55 01/18/02

Go up one level in this thread


On January 18, 2002 at 13:43:58, Sune Fischer wrote:

>On January 18, 2002 at 12:50:43, Chris Hull wrote:
>>
>>I haven't looked at the estimates in a while but the last ones I recall were on
>>th order of 10^65 unique positions. Basically, a very large number.
>>
>>Chris
>
>10^65 for the number of positions?
>
>That seems high to me.
>A very high upper limit with all 32 pieces on the board is:
>64!/(64 - 32)! = 5*10^53
>
>with only 31 pieces the number is even _less_:
>64!/(64 - 31)! = 1.4*10^52
>
>If we add these all the way down to two pieces, we still won't get much higher
>than 10^53.
>
>It is possible to get much lower upper limits:
>*) bishops can only go to 32 squares at most
>*) there are 8 pawns and 2 knights and 2 rooks, so thats a factor 8!*2!*2! less.
>*) if the white king has all 64 squares, then the black king can at most have 60
>*) the pawns can at most see 48 squares, not 64.
>and there will be many more illegal positions....

Uri Blass wrote a program to make an estimate.



This page took 0.01 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.