Hi Jacques, Jacques Basaldúa: <[EMAIL PROTECTED]>: >Hideki Kato wrote: > >>> It's rather odd. I'm checking the log file and then I will check the >>> source code to see if I have some artificial limits in there. > > >> Why odd? It all depends on the bias or policy of simulations. If >> there is a flaw in the policy, the score will converses to the score >> with some error, which will introduce some limit of scalability, isn't >> it? > >That is a very good point. Perhaps it is not the case with FatMan, >but that may surely happen. In this study no program is playing with >uniformly random playouts and perhaps only uniformly random playouts >will scale to perfection.
I don't think "only uniformly random playouts will scale to perfection" because what we need for playouts is not just a simple average of final scores but a maximum (in negmax sense) score. It should be the perfect evaluation function. In other words, as MC simulation is a way to get an average of a value, when applying it to optimization problems we need some way to focus the simulations to the _peak_ in a state space. It may be obvious when one consideres L&D problems where the best move that leads to the maximum score (live) is only one and all other moves are bad. At such positions it's almost no sense to simulate all legal moves with same probability. So, IMHO, biasing simulations is not just a speed-up technique but is essentially important. >Of course, I can imagine that reaching the >strength of Mogo_13 with uniformly random playouts can require a >number of simulations that is not feasible. I guess it should be done by only by UCT but to guide UCT to the best path requires good simulations. It may also be possible uniformly random playouts never get the strength of MoGo_13. >So I don't have any idea >about how to improve the study, but this is a serious limitation that >has to be considered: If you find some ceiling, the ceiling may be >attributed to the playout policy, not to UCT. Agree. -Hideki >Jacques. > >_______________________________________________ >computer-go mailing list >[email protected] >http://www.computer-go.org/mailman/listinfo/computer-go/ -- [EMAIL PROTECTED] (Kato) _______________________________________________ computer-go mailing list [email protected] http://www.computer-go.org/mailman/listinfo/computer-go/
