Author: Ed Schröder
Date: 04:03:59 09/27/99
Go up one level in this thread
>Posted by Bas Hamstra on September 27, 1999 at 04:23:24: > >Hello Ed, Hi Bas, >>From one thing came another, I had a critical look at move ordering again, >>made some changes, did intensive testing and there it was: 10-15% faster in >>the end-game and 25-30% faster in the middle-game. > >Congratulations. I too notice that small changes can have large consequences. >However in some positions system a is better and in some system b is better. >What exactly did you change? Just avoiding playing HOOGSTENS moves? Just zero the best-move in the hash table in case of an UPPER bound. It gave 8% for Rebel. The search then is forced to rely on normal move-ordering. >>After 18 years wrestling, fiddling and twiddling with move-ordering this is >>remarkable as I expected move-ordering was close to perfect in Rebel. I >wonder how much improvement there is still left in move-ordering. > >I too. Maybe for positions near the root use ETC and sort accordingly? So play >each move, look if the resulting position is in the hashtable. If no cutoff is >possible, you could improve sorting failsoftvalues. This is something I am >planning. Tried ETC too, it gave no speed improvement for Rebel. I do keep a special table for moves on ply=2. In cases of a fail-low (drop in score) on the best move so far it has proven to be very powerful when finding a new move in such cases. Ed >>I don't know what a 25% speed improvement means in terms of playing strength. >>Opinions are divided. I would say it gives 5-10 elo points. Others will say >>15-20 and they can be perfectly right too. >> >>Ed > >Regards, >Bas Hamstra.
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.