> When the programs select the best move to play it also knows what move > is the *most likely best move* for the opponent given search to that point. > > With speculative pondering all pondering goes into searching the reply > to that *most likely best* move. > > If the opponent plays a different move, this move will on average be a > worse move than the expected one. Although there was no gain in > pondering, my program has a better than expected position (on average).
I think this is too optimistic: it is surprisingly rare that any given board position has just one best move. E.g. I've analyzed complex 9x9 middle games (*) where the played move lead to a 0.5pt loss; in trying to find a win I've discovered 3 or more other moves that also lead to a 0.5pt loss. (After all, if this wasn't the case MCTS wouldn't work so well.) If we assume your opponent is roughly the same strength as you, then when they play an unexpected one the chances are they've not made a bad move, just an alternative good one. Darren *: I imagine 13x13 and 19x19 are more likely to have more than one equivalent move, but I'm not sure; it could be that this "average position sensitivity" is roughly the same at all board sizes and is a feature of the game. -- Darren Cook, Software Researcher/Developer http://dcook.org/gobet/ (Shodan Go Bet - who will win?) http://dcook.org/work/ (About me and my work) http://dcook.org/blogs.html (My blogs and articles) _______________________________________________ Computer-go mailing list [email protected] http://dvandva.org/cgi-bin/mailman/listinfo/computer-go
