Author: Albert Bertilsson
Date: 09:58:53 06/27/03
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On June 27, 2003 at 10:46:08, Sune Fischer wrote: >On June 27, 2003 at 08:13:53, Albert Bertilsson wrote: > >>Just wanted to share my latest findings and warn you from making the same >>mistake (or maybe I just point out the obvious). >> >>I've always been proud to have a very fast movegen, doing perft calculations >>very fast. I optimized the movegen alot, and always saw playing strength >>increasing. I use a legal move generator and always saw the cost of verifying >>legality to be minor. Lately however I've noticed that the engine performance >>isn't that great (compared to other engines) inspite of the fast movegen. So I >>started digging today and the numbers struck me as lightning... >> >>As I've improved moveordering very much with hashtable/iterative deepening, >>killer moves and history tables the effective BF is now much lower. The lower BF >>now means that very few moves of all the generated ones are actually ever made. >>This means that the cost of generating legal moves have increased incredibly >>much. >> >>It's really anoying to notice that something you though was very good now is on >>the list of improvements again =(. >> >>/Regards Albert > >What that saying with premature optimization being the root of all evil? :) > >Well it think it is correct, and probably a typical mistake to spend oceans of >time optimizing one thing only. > Lucky me I didn't have oceans of time to optimize it. Although some time has been spent on optimization I consider it well spent since it radically improved my engine. A was happy that I got it right, sadly such a thing doesn't last. My movegen is currently good enough to be the best part of my engine and I will not spend time on it any more, I'd rather improve other things, although nowadays I have almost no time for Sharper =(. >I found a good post by Bruce Moreland about that, I just can't say it any better >myself :) > >http://fortuna.iasi.rdsnet.ro/ccc/ccc.php?art_id=177933 > Bruce is a wise man. >-S.
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