Mark Boon wrote: > On 16-jan-08, at 11:54, Christoph Birk wrote: > >> I think this is very wrong, like allowing suicide. >> If you allow (or forbid) moves that cannot really (should) be played >> in the >> random games you are not sampling the true status of the board. > > I think most people take a much too dogmatic point of view on this > issue either way. Maybe by allowing suicide you don't sample the true > status, but does it statistically matter? If you hold this stand-point > then you should also detect board repetitions. I bet most if not all > only check for ko because checking for repetition is too time-consuming. It matters a lot. The biggest advance in MC has been modifying the play-outs so that they are not completely random - but instead tend to play more realistic moves. For instance my play-outs tries a random defense to an atari move.
So it makes no sense to allow a move that is almost certainly horrible in the play-outs. Even if your group is dead, at least use your turn in a more productive way. This gives a more realistic picture of the value of a position statistically. Now it's a different issue whether the extra speed gained by not testing for suicide is worth the degradation of quality. But as you get into heavier play-outs, the time saved by heroic measures like allowing suicide becomes very minor because the majority of your time is spent judging moves and massaging the move list - steps that can be avoided if you are not picky about the moves allowed. So yes, you can get ridiculously fast play-outs if you "throw out the baby with the bathwater", but you have to give up a lot of that speed if you want high quality Mogo-style play-outs. Board repetition detection is not in the same league as allowing suicide. 99.9% of the benefit of knowing about position superko is handled in the search tree where you CAN check for repetition. In the play-outs the advantage of testing for repetition is almost non-existent. Suicide on the other hand is a move that is almost certainly horrible. - Don > > My question would be, would choosing either way matter? If it matters > you do something about it. If it doesn't matter you don't care. For me > multiple suicide and board repetition fall in the category where they > don't matter. The cases where it makes a difference are so few that > you can play for a lifetime and encounter it maybe once or twice. > Maybe with MC playouts it would make the game shorter when > multiple-suicide is not allowed. If that's the case then that's a > reason to do something about it. But even with MC I doubt you save > more than a few moves on average. > > Not allowing to play on a point that was at some point illegal for one > side does matter a lot. Groups with one (false) eye would be alive. So > so I'm sure people won't use that. > > Mark > > > ------------------------------------------------------------------------ > > _______________________________________________ > computer-go mailing list > [email protected] > http://www.computer-go.org/mailman/listinfo/computer-go/ _______________________________________________ computer-go mailing list [email protected] http://www.computer-go.org/mailman/listinfo/computer-go/
