Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Mate in 1 - but Fritz 6 needs 1 hour!!!

Author: Colin Frayn

Date: 01:35:07 08/11/00

Go up one level in this thread


On August 10, 2000 at 20:06:15, Adrien Regimbald wrote:

>Fritz is designed to play well in a "normal" game of chess.  Fritz would have
>absolutely slaughtered the opponent a LOOOONG time before that position arose
>had the opponent been playing as per the sample line leading to that position.
>The chances of a position like that ever coming up in a real game of chess are
>about nil.  If I were Frans, I wouldn't even give this position a second of my
>thought (well, beyond possible implications that Fritz' capture extensions are >a bit too greedy..).

Fritz is a chess engine.  This is a chess position.  Fritz can't do it despite
the fact that a 5 year old child could easily see the mate in a few seconds.
This means that Fritz has failed.  The problem is not that Fritz can't do _this_
position, but rather that Fritz spends over an hour on a problem which should
take it a tiny fraction of a second.  It shows that the algorithm is doing
something wrong.  Imagine a ramp down in problem complexity with an associated
ramp-down (not necessarily linear) of time required on average.  It's still
going to be taking far too long to solve other pretty obvious problems which
aren't as contrived as this one.

Checking for mates before you do any searching is not only fast, but it vastly
improves search times on positions like this.  I've often seen ColChess analyse
4 or 5 ply deeper in some positions than, say, Crafty in the same time.  That
was because there are lots of CMs flying around to avoid.

Cheers,
Col



This page took 0.02 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.