Computer Chess Club Archives




Subject: Move Ordering at the Root

Author: Dan Homan

Date: 14:12:16 09/15/99

I was reading the crafty source again the other day and noticed that
Bob has a special function to improve the move ordering at the root
of the search.

I really didn't feel like writing such a function last night, but I
thought instead to use the values returned by the search itself to
improve the move ordering at the root.  I know that I only get an
accurate value for the best move, but I thought that my fail-soft
search might return useful numbers for the other moves as well....

Implementing this was pretty quick and easy: there were a couple
of pit falls, but the total changes were about 5 lines of code.
Previously I simply used the same move ordering at the root that I
use at all other nodes.

The improvement was amazing!  I got a full ply in many positions and
about a half-ply in many more.   It improved my solution times on WAC
noticably and seems even better in quiet positions.

I know that my solution was a quick kludge, so I am wondering what
other people do for move ordering at the root of the search.

 - Dan

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.