Erica and many Faces do not set c = 0, so there are many strong go programs that do not set c to zero. Fuego and Mogo use c = 0. I'm not sure about others.
David > -----Original Message----- > From: [email protected] [mailto:computer-go- > [email protected]] On Behalf Of Jason House > Sent: Tuesday, October 26, 2010 6:01 AM > To: ???? ??????; [email protected] > Subject: Re: [Computer-go] Monte Carlo (upper confidence bounds applied to > trees) > > It looks like your example is using average win rate instead of an upper > bound. Rather than M/N UCT uses M/N + c*log(N1+N2+N3+...)/sqrt(N) > > where Ni is the total simulations of the ith move. That extra term means > moves with initially bad results will be revisited. Stronger go programs add > in some other terms and set c=0, but that isn't UCT. > > Sent from my iPhone > > On Oct 26, 2010, at 6:43 AM, ???? ?????? <[email protected]> wrote: > > > Hello all! > > I would much appreciate if someone could explain me what exactly "upper > confidence bounds applied to trees" is. > > > > I'm still not sure that UCT works good. > > > > For example, I have a position with two possible moves (a1 and b1): > > > > O > > / \ > > (a1) (b1) > > > > > > First random game (using a1 as first move) returns 0, second (b1) returns > 1: > > > > O > > / \ > > (a1) (b1) > > (0/1)(1/1) > > > > > > Ok, let's try to explore b1 move (the program likes it, because uct of a1 > = 0): > > > > O > > / \ > > (a1) (b1) > > (0/1)(1/1) > > / | \ > > a2 b2 c2 > > > > > > a2 returns 0, b2 and c2 returns 1: > > > > O > > / \ > > (a1) (b1) > > (0/1)(3/4) > > / | \ > > a2 b2 c2 > > 0 1 1 > > > > > > So the program will explore b2 and c2 (starting from b1), but maybe a2 is > the only refuting move. Maybe a1 is better, but the program will continue to > explore b1, because utc of a1 is 0 and utc of b1 is more than 0. > > _______________________________________________ > > 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
