Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Closest link between a statistic and playing strength

Author: Dann Corbit

Date: 22:13:34 12/06/01

Go up one level in this thread


On December 07, 2001 at 01:06:55, Russell Reagan wrote:

>There are all kinds of statistics that you can formulate about a chess program,
>the most notable being nodes per second. What statistic *should* imply a
>stronger program? Obviously NPS is nice, but it's certainly not something you
>can use to say that one program is stronger than another. I'm thinking that
>number of plys would be a better indicator of strength, and I toyed with the
>idea of some kind of nodes/ply kind of statistic.
>
>The nodes/ply statistic obviously would give different results in different
>positions, but for testing your own program, it seems like a good tool. For
>example, if you did an 8 ply search and searched N nodes without the use of a
>transposition table, and after implementing the transposition table you only
>searched N/2 nodes (I have no idea what the actual gain would be) then that's
>obviously good. Then again, that indirectly implies a deeper search, which makes
>this statistic boil down to plys/sec (in the same position of course, with the
>same program, otherwise results would vary widely).
>
>Any ideas about other statistics or comments about my thoughts I've thrown out
>here?

There are lots and lots of statistics you can use.  All of them are pretty well
useless except won/loss/draw against opponents of known strength.

Here are some reasons why:
Suppose that I have a material only evaluation, and absurd pruning rules.  I can
search like the burning blue blazes, but it will play like total crap.

Suppose that I tune my engine to run EPD test suites.  I may get better
performance on those suites, but far worse in actual games.

Suppose that I have a slow searcher.  The NPS comparisions make no sense against
a fast searcher.

Plys are probably one of the best indicators.  However, if the eval is no good,
neither are the plys worth anything.

Test suites are a fairly good indicator -- but they are a necessary and not
sufficient condition for powerful game play strength.

In short "the proof of the pudding is in the eating."



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.