Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Crafty and single-computer winboard matches

Author: Ed Schröder

Date: 03:07:49 10/07/99

Go up one level in this thread


>Posted by Robert Hyatt on October 06, 1999 at 15:30:48:
>
>I'm going to make a list of all the reasons why two programs, one computer,
>is a bad thing to do:
>
>1.  a program might not be well-adjusted in how it uses its time when it is
>not allowed to "ponder".  Crafty is an example.
>
>2.  a program might not be well-behaved and do some unexpected computation
>after it sends the move to the referee program.  IE in crafty, I send the move,
>then I do the learning stuff after 10 non-book moves have expired.  This 'learning
>cycle' can take 2-3-4 seconds with a really large book and a long opening line
>in the book.  Imagine what that does to a game/1minute time control that many
>are using in winboard/xboard?
>
>3.  a program (ie crafty) might do other things after it annouces its move,
>such as malloc()'ing a large buffer for (say) learning or whatever.  What does a
>large malloc() do to the other program?  swap it out?

Never thought of this. This is a real killer, I agree. If done on purpose you
win every game :-)

>4.  A program (ie chessmaster) might poll for input, consuming 1/2 of the cpu
>even though it is not 'thinking'.

Another true point. Every program needs to poll for input. Asking the
keyboard / mouse for input are expensive (slow) operations. In Rebel
I have a counter that makes sure to look for input after 500 evaluations.
If I decrease the value to say 50 or 10 the NPS of Rebel drops
tremendously (forgot about the exact slow-down).

Thus the opponent program will ALWAYS slow-down yours and you can
only guess how much that is.

>There are _too_ many things a program _might_ do.  I'll bet not one person
>gave any thought to a "learning cycle" in crafty, yet it does it in every
>game. And it steals 2-4 seconds of time from the opponent.  In short time
>controls, that might be important.
>
>If I _know_ people are testing like this, I'll bet I can raise Crafty's rating
>by 100 points minimum.  I won't say how, but it shouldn't take too much
>imagination to figure it out.  :)  And with that said, why bother testing in a
>way that is obviously potentially unreliable.  For fun, sure.  But reporting
>the results as "A beats B" is not very scientific...  A might not actually
>be able to beat B, he just might have a smarter programmer that takes
>advantage of a flawed testing methodology...
>
>:)
>
>Bob

Strong points Bob. Still people are in love with the system as you only
need one PC and have a lot of fun. If only its results are judged in the
way it should. And in no way you can compare eng-eng matches on 1 PC with
eng-eng matches on 2 PC's.

Ed

PS, match score sofar PB_ON vs PB_OFF 17.5 - 8.5





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.