Author: Alex Newman
Date: 19:30:05 03/09/05
Go up one level in this thread
On March 09, 2005 at 22:10:58, Robert Hyatt wrote: >On March 09, 2005 at 21:19:51, Alex Newman wrote: > >>On March 09, 2005 at 21:12:52, Michael Yee wrote: >> >>>On March 09, 2005 at 20:27:09, Alex Newman wrote: >>> >>>>I can take the source code of Crafty and make an engine stronger then Crafty in >>>>less then a week. >>> >>>Not to be (too) confrontational, but have you actually accomplished this feat, >>>say, in a private experiment? >>> >>>There was someone here a while ago who was trying to get people to bet him a >>>large sum of money that he couldn't improve crafty by some amount of points >>>(maybe 100?). >>> >>>I'm skeptical of these kind of claims because if it were possible to improve >>>crafty by that much, it would almost be commercial strength (according to WBEC >>>ratings)... So why wouldn't that person just write a commercial-level engine >>>from scratch (given that he has the last "secrets" anyway)? >>> >>>Michael >> >>I didn't say 100 ELO. I just said 'improve'. >>No, I didn't try it. But try adding checks in quiescent, history and better >>futility pruning, and you should get at least 30 ELO. >>I think Crafty could be better in tactics. > > >1. crafty uses history. always has. > >2. older versions used checks in q-search. you can see from the comments in >main.c when they were removed. The version with was absolutely no better than >the version without, and the code was simpler without. > >3. "better futility pruning" I don't know about. It is already risky enough, >but who knows what can be improved there... Thanks for the answer Prof. Hyatt. I have a great respect for you and Crafty. - By history pruning, I mean reducing search depth for moves with low history value (many conditions apply of course). I know Crafty uses history for move ordering, but am not aware you use it for pruning (didn't check the most recent Crafties). - It's seems to be common experience shared by many that checks in q-search help tactics, but again they shouldn't be done always. Some think that using always R=3 and checks in q-search for null moves only is a good idea. - By better futility pruning, I mean doing pruning for nodes other then leafs, but with much higher material margin.
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.