I agree this is a big problem, especially when there are unbalanced semeai on the board. An unbalanced semeai is one where the playouts have different numbers of plays for each side. For example if there are approach moves required, so capturing one side requires moves played in a particular order, and capturing the other side works with moves played in any order.
I have some ideas to fix this, but haven't tried them all yet. My first, small change made the program significantly stronger. David > -----Original Message----- > From: computer-go-boun...@computer-go.org [mailto:computer-go- > boun...@computer-go.org] On Behalf Of Stefan Kaitschick > Sent: Monday, September 07, 2009 6:32 AM > To: computer-go > Subject: Re: [computer-go] two won semiais = lost game? > > > It is obvious that the current mechanism is bad. And another problem on > > the > > wrong evaluation is the amplification of the error. When there are > > unresolved > > life/death or semeais on the board, typical MC programs become weak > > because > > of the instability of the simulations. > > > > I think that we need a new algorithm to combine the UCT information into > > the > > playout policy. I have already done a lot of experiments in this area, > but > > not > > yet succeed. However I believe this idea will be the next breakthrough. > > > > -- > > Yamato > > Remember quiescence search in chess programing. There, captures are > executed > before the evaluation function is invoked. Maybe a kind of quiescence > search > is needed here too. In the case of go, semiais could be played out(allways > trading an equivalent number of moves locally), before the actual > search for a move begins. There are problems with this: finding the local > battles, trading moves realistically, compensating for lost ko threats, > attempting to playout a "hot" fight, ect. But getting rid of useless > combinatorial explosions would be worth a lot. > > Stefan > > _______________________________________________ > 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/
