Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: ply search vs elo rating - proposed formula

Author: Graham Laight

Date: 09:18:58 10/21/99

Go up one level in this thread


On October 21, 1999 at 09:19:11, Jeremiah Penery wrote:

>>Firstly, one of you said that there was a theoretical max elo rating of 3000.
>>Presumably, this is calculated by correlating elo rating with proportion of
>>draws achieved between 2 players of that level. Is this correct? Has anyone done
>>this work.
>
>I'll try to look up where I found this... It wasn't exactly 3000, I think, but
>somewhere around that number.
>
>>Secondly, the time the computer takes theoretically doesn't matter (though it is
>>well known that if a computer plays quickly, the human opponent tends to play a
>>lot worse).
>>
>>Thirdly, in view of the estimated figures for Hiarcs shown above, I have decided
>>to modify Laight's equation as follows:
>
>
>Hiarcs may simply have a greater K than 0.15, which you were using before.  DB
>almost certainly does.  Although the new formula looks pretty good. :)
>
>
>>Laight's Equation
>>=================
>>
>>Version 2: 21/10/99
>>
>>elo rating = log((Ply * K * C1) + C2) * C3
>>
>>Where ply = ply search depth
>>K = Knowledge Level
>>C1, C2, C3 are constants.
>>
>>The extra constant, C1, is necessary to compress the range of results being
>>produced.
>>
>>As before, K is calculated as follows:
>>
>>Kn = % of all the useful chess knowledge the program has
>>K = Kn/(100 - Kn)
>>
>>If C1 = 0.1, C2 = 1.3, C3 = 13500, and K = 0.2, this yields the following
>>results:
>>
>>Ply 1 elo = 1628
>>Ply 10 elo = 2377
>>
>>This is well in line with the numbers Joshua Lee suggested above.
>>
>>If Laight's equation applied to Hiarcs and Deeper Blue is accurate, it implies a
>>K of 0.2, which would mean that both computers have about 17% of all the useful
>>chess knowledge.
>
>DB has a lot more knowledge than Hiarcs does.  Also, DB was searching a lot more
>than the 14-ply that Joshua was saying - it searched 14 + 30(+) ply in most
>interesting lines.  It's really difficult to determine an accurate 'depth' most
>of the time, because for each program it will be different, based on the number
>of extensions done.  Hiarcs probably extends more than most other micro
>programs, but DB does a lot more even.
>
>Unfortunately, this formula probably won't work for humans, because it's
>impossible to determine a search depth.  Therefore we can't use humans as a
>gauge for the accuracy of the 'K'.
>
>I figured for myself that I have only 5% of chess knowledge (K=0.05), and that I
>search 2-ply.  Based on this, I got a rating of 1583.  This is a bit too high, I
>think. :)
>
>Jeremiah

I must admit I'm having difficulty making the numbers behave correctly in the
light of this new information.

I'll keep working on it...




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.