Many Faces uses Progressive widening only. I think they are pretty similar, with progressive bias perhaps a little better when well-tuned (from private communications with people who have tried both). On 19x19 I think progressive widening is faster and less memory, but I only did few small experiments with progressive bias, so I may not have found an efficient implementation.
David > -----Original Message----- > From: [email protected] [mailto:computer-go- > [email protected]] On Behalf Of Brian Sheppard > Sent: Sunday, January 20, 2013 8:45 AM > To: [email protected] > Subject: Re: [Computer-go] Progressive Bias, progressive widening > > I started with just progressive bias, and I have not seen any reason to > add progressive widening. > > My experiments are on 9x9. Like you, I wonder whether additional > concepts will be necessary when the board is larger. > > Brian > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of ds > Sent: Sunday, January 20, 2013 10:51 AM > To: [email protected] > Subject: [Computer-go] Progressive Bias, progressive widening > > Hi, > > I know, this topic was in the list a while ago. My problem is, as in all > science, nobody publishes negative results:) > > Oakfoam uses both, progressive bias and progressive widening. My > understanding is, this is state of the art in many mc bots, at least the > theses I read used both. > > Both is working well in oakfoam. Now I turned off progressive widening > and tuned progressive bias carefully (good scaling of the bias and > improved decay functions). I got the same playing strength as with both > (bias and > widening) before on 9x9 against gnugo, but I can not improve anymore > with progressive widening turned on again. > > My interpretation is: Progressive bias is the superior concept, but it > is easier to use progressive widening. > Progressive widening is not sensitive to the ratio of the pre knowledge > value of two moves, only the better move must be unpruned first, but > progressive bias is sensitive to the ratio between the pre knowledge > values. > > It may be even more difficult to improve the progressive bias on 19x19, > so there might be a reason to use widening, but at the moment I feel I > should try without? > > Am I wrong? > > Detlef > > > _______________________________________________ > Computer-go mailing list > [email protected] > http://dvandva.org/cgi-bin/mailman/listinfo/computer-go > > _______________________________________________ > Computer-go mailing list > [email protected] > http://dvandva.org/cgi-bin/mailman/listinfo/computer-go _______________________________________________ Computer-go mailing list [email protected] http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
