On Tue, 2008-08-12 at 09:55 +0900, Darren Cook wrote: > > [The pro] was also a bit "unlucky" in the sense that Leela did not > > understand it > > was dead lost. > > > > I use quotes because had it understood better it was losing, it would have > > put up more of a fight :-) > > My first impression of watching the game was that Leela was handicapped > by having a handicap. By that I mean it would have seen itself so far > ahead for the first few moves that is was playing arbitrarily.
I was blasted for making that observation many months ago concerning the possibility of handicap matches on CGOS. I thought it not a good idea for Monte Carlo players because each player starting with a dead won or dead lost game. The response was that it didn't matter, the programs would still fight. So I yielded to the opinion of others since I am not a go player. I now think they were probably right. MCTS still tries to maximize the chances of winning. If you are up 8 or 9 stones, that is STILL the right strategy isn't it? Also, if you are down 8 or 9 stones, maximizing your winning chances is still the right strategy, right? I'm trying to come up with some kind of analogy to real life. How about investing your money? Let's say you play a game where the goal is to turn 500 thousand into 1 million dollars in 10 years. Double your money in 10 years is not particularly difficult so if the only thing that matters is winning this game then you would use very conservative investments. This is like being up 9 stones because in theory you have a relatively simple task to perform, just double your money. The temptation is to be foolish by thinking if you are a lot more aggressive, you can get ahead of the game and get there faster. Surely, if you have a good year or two, you can coast the rest of the way! Have you ever been with someone who is about to run out of gas? They want to drive FASTER thinking that if they get there faster, they will use less fuel. Or maybe they just get anxious which causes you to drive a little faster. > This is a direct consequence of the UCT algorithm playing for the win, > instead of trying to maximize the score. I'm fine with that (please see > the archives for numerous passionate discussion on the subject), but > surely you need an opening book to allow for the fact that evaluations > are going to have a high error margin in the early game? > > (I'll go out on a limb and say black 3 was a mistake; I'm sure it is a > win at 0.5pt komi, but I strongly suspect it is dubious at 5.5pt komi or > higher.) > > >From another angle: if a UCT computer program is being given a handicap > against a stronger player it should lie to itself about the komi at the > start. It could then gradually adjust komi so it is at the correct value > by the early middle game (e.g. move 6 in 9x9 go, move 30 in 19x19 go). > Or it could keep adjusting komi (until it reaches the actual komi) so > that it thinks it is only just winning. It could turn out that the best strategy is simply to let the opponent play desperately and not over-react, because to have any chance when giving 9 stones you must in some sense over-play it. - Don > > Darren > > _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
