I agree that probably most players play as you say. But it's difficult for me to believe that the very best players don't know if the are wining or not.
I think if I had the skill of a professional, I would make it my business to know, ESPECIALLY if it were really close. I'm talking about the cases where a UCT player thinks it's winning with high probability. If a UCT player knows this, I'm sure a really strong professional knows. It's a different story when several groups are in question and a UCT players is "skillfully" assessing the odds. But I don't think we are talking about that case. UCT doesn't start playing too bizarre until a win is in the bag for one of the players. I've seen this for myself. The score gets about 95% but there are still many ways to lose if you play stupid, but the MC player knows carefully takes care of business - sealing this and that off so that there is no chance. Many times I've seen it throw away 1 or 2 points by not claiming an extra point right next to the point that it does claim. In some of those cases I counted it off myself and to my amazement it just didn't need that point and it was probably a random choice. But in those cases there was no chance of tricking a human. Nevertheless, the human sometimes is under the impression the program made a series of "really bad" moves and STILL WON, making the human feel frustrated. But really it was not like that at all. - Don ivan dubois wrote: > Hello Don, > > I think you are mostly right, but there is something you seem not to realise. > MC players are very good at "scoring". They know when they will win for sure > by 0.5. However, human players, even strong players, generaly never have such > accurate counting skills. So if they are ahead by 0.5, there is no way they > can anticipate it at as a sure win, because it would require amazing couting > skills. Actually, a lot of strong players never count during the course of a > game, especialy during fast games. > So often, the most rational way of playing is to be conservative with the > points you have, and just always play the natural, conservative defending > moves. It may be too hard for human to reason about "probability of winning", > it is easier to reason about points you have or not. > Of course, i think the ultra rational way based on accurate couting by MC > programs is a great strength they have. Its a specific strength of MC that > human, unfortunately for them, do not have. > > ----- Message d'origine ---- > De : Don Dailey <[EMAIL PROTECTED]> > À : computer-go <computer-go@computer-go.org> > Envoyé le : Mardi, 22 Janvier 2008, 21h47mn 39s > Objet : Re: [computer-go] Is MC-UCT really scalable against humans? > > > > David Fotland wrote: > >> I didn't say that :) Please read what I wrote. >> >> > No, I was thinking ahead, not quoting you. I was just covering my > bases, anticipating what I thought my be a likely response (and not > necessarily from you.) > > >> The UCT programs often find moves that are unconventional. This makes >> patterns that aren't in the database, so the traditional programs can't >> cope. People are a little more flexible, especially strong players, and can >> still find good responses to unconventional moves. >> >> I don't know what you mean by "unsound". That's chess terminology and I >> think it refers to a trick move that should lead to a loss against good >> play. >> > Unsound just means a move that is really wrong. It could be tricky to > find the right move or might just be an outright bad move. > > > >> In go we talk instead about moves that lose points. UCT programs >> often play moves that clearly lose points in an attempt to maximize the >> probability of winning. These moves are unconventional because people learn >> the optimal moves in standard situations. Weaker players and traditional >> programs can have trouble finding the best response to these non-optimal >> moves. >> > There is an isssue whether these are really non-optimal or not. To me > an optimal move preserves the win if a win is possible and nothing else > matters. I think it's elegant to not play greedy when another moves > is better in the game-theoretic sense. > > >> So the UCT programs gain strength for two reasons, first, because >> the maximize the probability of winning rather than maximize the score. And >> second because this causes them to play unconventional moves, which make the >> game more difficult for their opponent. >> > They don't do this. By the time they start playing unconventional > moves they have already won or lost the game. I think this is a huge > misconception. It's true that they may fail to defend a big group and > attack a small group because it is slightly more likely to win - but > that's a pretty rational thing to do - going for the big group may be > more human-like but less logical so I don't care if that confuses a > weaker opponent. (I suppose the blunder the weaker player would make > is to defend the big group and not give due resistance to defending the > small group - but for sure there is no good reason to program a program > to make the irrational decision because it makes weak players more > comfortable.) > > >> There is nothing inherently wrong >> with playing unconventional moves that are still good. Strong players do it >> whenever they can to make the game more difficult. >> >> > I would imagine that the stronger you are, the more you would be > concerned with playing for the win instead of points. > >> David >> >> >> >>> Please don't say the style is to "find an unsound move that >>> is >>> difficult to defend", that's not what it's trying to do, it's just >>> trying to find a move that it is IMPOSSIBLE to defend, and if it >>> >>> - Don >>> >>> >>> >>> David Fotland wrote: >>> >>> >>>> I share this opinion. 9x9 was a good simple test to get things >>>> >>>> >>> started, but >>> >>> >>>> go is a 19x19 game. 9x9 has limited interest. An analogy for chess >>>> programmers would be if a group of people worked on programs to solve >>>> >>>> >>> rook >>> >>> >>>> and pawn endgames. This kind of chess endgame is a good test to try >>>> >>>> >>> out >>> >>> >>>> algorithms, but if they claim to be making strong chess programs, at >>>> >>>> >>> some >>> >>> >>>> point they have to implement the full game. In go it turned out that >>>> >>>> >>> to be >>> >>> >>>> good at 19x19, some new algorithms were needed (patterns and heavy >>>> playouts). I think that to take the next step in 19x19 strength the >>>> programs will need to be stronger at life and death. >>>> >>>> >>>> >>>> The UCT-MC programs do particularly well against traditional programs >>>> because they expose the brittleness inherent in the pattern databases >>>> >>>> >>> they >>> >>> >>>> use. Strong humans are not so easily beaten by playing >>>> >>>> >>> unconventional and >>> >>> >>>> somewhat inferior moves. >>>> >>>> >>>> >>>> David >>>> >>>> >>>> >>>> Personally I think 9x9 is good for trying out ideas. But in the end, >>>> >>>> >>> if it >>> >>> >>>> doesn't play well on 19x19 then I don't care one bit how well it >>>> >>>> >>> plays on >>> >>> >>>> 9x9. Just my opinion of course. >>>> >>>> >>>> >>>> Mark >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> >>>> >>> --- >>> >>> >>>> _______________________________________________ >>>> 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/ >>> >>> >> _______________________________________________ >> 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/ > > > > _____________________________________________________________________________ > Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! Mail > http://mail.yahoo.fr > _______________________________________________ > 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/
