Jonas Kahn wrote: >> I don't see that, but then again I am not a very strong player >> myself. What I notice is that it plays very "normal" until it's >> pretty obvious that it's losing, not just when it varies slightly from >> 50% but when it doesn't vary much from zero. However, it does play >> more desperately once it varies significantly from 50% but certainly not >> "meaninglessly." >> >> I don't like using the words "good" and "bad" when describing the >> quality of the moves because I try to use terminology that's more >> descriptive (although I fail miserably many times.) In a lost >> position how do you distinguish one move from another when they all >> lose? It sounds funny to me when you say (in so many words) that >> once the program is losing it starts playing "bad moves." >> > > At first move, the position is lost or won for one of the two players. > Yet I am sure you could consider that some of the moves are good or bad. > The only thing that matters is: > Does this move increase my probability of winning against this opponent ? > If two moves have the same result, which one is more beautiful ? > MC programs are not that smart. I'm talking about positions where it's so clear that even MC programs know it's a win or loss (at least "know" with high probability.) This is really the only case where there is a problem. If there are reasonable chances (in practical terms) then MC doesn't have this ugly behavior.
- Don > I do not expect a computer to play Lasker way any time soon, so we might > have to change the first criterion into ``against a generic opponent". > > Now when MC goes to the rampage, it's usually LESS efficient than if it > was a little less desperate. The post of Baudis explains that well. I > think the problem is that MC is overevaluating the probability that an > opponent does not answer an easy threat, and, if playing against a > human, lessen the probability of small imprecisions. > > When losing, look for an overplay. But a reasonable overplay... > > > >> Since this is a subjective quality can we use a subjective term such as >> "normal" to describe moves that are cosmetically appealing to us? >> And perhaps "ugly" to describe moves that are not? >> >> My feeling is that in lost positions, the only thing we are trying to >> accomplish is to make the moves more cosmetically appealing (normal) and >> at best improve the programs chances of winning against weak players. >> After all, if the program is in bad shape, then to be completely >> realistic it's probably going to lose to the player that put it in this >> bad shape. Unless of course the program is being upset by a much >> weaker player which can occasionally happen too. We can't reasonably >> expect that if a program is quite sure that it is losing that the >> program that it is beating it is not going to be aware of this too. >> >> It's also a bad mistake in my opinion to try to coerce it into playing >> moves that are "normal" when an increasing amount of "desperation" is >> indeed called for. I have presented anecdotes before about how chess >> players have won games based on not playing as if things are normal when >> they are losing, but instead suddenly playing differently which usually >> consists of violating general principles and "normal" play. >> >> Again, I feel that this effect of moves that are not normal kick in >> mostly when the position is very close to 0 or 1. So what we are >> looking for is AT BEST a very minor improvement and we are wasting a lot >> of energy on this. >> > > Agreed. > > >> If the goal is to make the moves more cosmetically >> appealing I can respect that more - that is realistic and probably even >> easy to accomplish (and then the goal is to do it without weakening the >> program too much.) >> > > Here I don't agree. > Why should that weaken noticeably the program ? Same situation as > before, it happens for won-lost positions: minor change in performance. > > >> It's also being considered to use this to cover over some other weakness >> such as nakade where the program doesn't understand the actual end of >> the game and is thinking it has lost by 2 or 3 stones when in fact it >> has a win. Aside from the fact that this is a fairly rare >> occurrence, I believe it should be addressed directly, not with a >> superficial treatment of the symptoms. >> >> So if you can make it win slightly more lost games by playing as if >> nothing is wrong, then more power to you. It doesn't seem reasonable >> to me that you should be able to do this by feeding the program false >> information. You are effectively saying, "you are losing, be happy >> with that." >> >> By the way, if this is to work (for instance for cosmetic reasons) I >> don't think you can apply this gradually or based on previous >> information. What if you are losing and the opponent plays a >> blunder? After all, this is what has to happen since the program is >> losing. You have to apply this based on information learned from the >> current move you are searching. You can't gradually fold it in as the >> game progresses and expect anything useful. >> > > I also agree about that. In fact, I think that in my previous suggestion > to Hideki, winning rate after say 1000 simulations should be checked to > be about that expected, and if not, komi should be adjusted again. > > > >>>> After all, the aim of tinkering with komi is to avoid that the computer >>>> plays nonsensical moves, but it should know whether he must fight or >>>> calm down. >>>> >>>> >>> Agree. So, it's important _when_ adjust komi or apply my method. My >>> object is to keep winning rate around 50%, which yields good moves. >>> >>> >> First of all, you won't keep the rate at 50% no matter what you do. At >> some point the programs are able to completely resolve the position and >> this happens surprisingly early in many cases with good programs. >> If it's actually winning, then if you deduct a komi to convince it is >> losing, you greatly increase the chances that it really will lose. If >> you increase the komi to make it "try harder" to win a won game, it >> won't start playing meaningful moves and you risk losing. >> >> You see, the problem is that once the score is significantly extreme in >> either direction, there is no much you can do anyway, a single komi >> point will change it suddenly to the OTHER extreme. But this is really >> where most of the action is, so you have a catch-22. >> >> Go ahead, try this experiment: When the program is winning by over >> 95%, see what happens when you tell it to "go for more" and see if >> makes it win even more games. >> > > Agreed. That's why I think an evaluation function taking score into > account is more reliable. As I said, with a very low importance of > score, there's no reason to get weaker. > Bouzy had indications that with a ``half-low'' (1/50 instead of > 1/10000), you even could get some improvement. > > >> I honestly believe you are barking up the wrong tree if you are looking >> for program strength improvement. >> > > Probably true. I think the main motivation should be cosmetic. > On the other hand, changing the evaluation function is probably very > easy (a guess, since I do not program), so the pay is not that bad. > > Jonas > _______________________________________________ > 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/
