Hi Guillaume, I think we talked about this before, but others may be interested as well. In my opinion the ICML paper on Rave has several weaknesses. It's been a while since I read the paper, but here are some I remember:
(1) They compared Rave to plain UCT. If they would have compared it to a more sophisticated implementation (like the best Mogo before Rave) they probably could not have shown a spectacular improvement. (2) The paper suggest that you should add an upper confidence bound to the rave values. Although they didn't actually make this explicit, because IIRC the paper failed to provide an actual value for the constant c, I guess most people naturally assume it to be positive. However, Rave is already a greedy heuristic, so if anything you should probably subtract the confidence bound. Depending on the playout policy, adding an upper confidence bound to the rave values can push some terrible bad moves up (like playing on 1-1). The reason seems to be that such moves are normally sampled very infrequently (so the UCB will be higher), and when they are selected (e.g. for a big capture deep in the playout) they correlate more with winning (so the value will also be higher) without generalizing to earlier positions. Best, Erik On Wed, Feb 6, 2008 at 10:47 AM, Chaslot G (MICC) <[EMAIL PROTECTED]> wrote: > I also implemented RAVE in Mango. There was a few points of improvements > (around 60 Elo points with gnugo as reference), but as much as in the paper > of Gelly and Silver :( (around 250 Elo points if I remember well) > > It might be that the effect of RAVE depends a lot on the simulation > strategy. Indeed, sometimes my RAVE was playing very good moves but also very > bad ones. > > Guillaume > > -----Original Message----- > From: [EMAIL PROTECTED] on behalf of Magnus Persson > Sent: Wed 06/02/2008 00:42 > To: computer-go@computer-go.org > Subject: Re: [computer-go] More UCT / Monte-Carlo questions > > Quoting Gunnar Farnebäck <[EMAIL PROTECTED]>: > > > I have never managed to implement RAVE successfully. It made my > > program significantly slower but no stronger even at a fixed number of > > simulations. > > I get a small effect from RAVE, My rationalisation is that if the > program is rich with other features to improve performance RAVE may > not add that much. > > -Magnus > > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ > _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
