That's an interesting idea - factoring in knowledge about the "variability" of a position. Certain parts of the board are going to be stable with alternating play - you attack, I defend, the position remains stable. Other parts of the board are less well-defined. On the 9x9 board, conflicts easily spill over; everything is inter-connected until the end-game. On the 19x19 board, it's possible to establish stable groups, and the action usually happens on the borders. Factor in seki, ko fights, etc. Simply varying komi as some pre-ordained function of move number is unlikely to have enough granularity to cope with the structure of a particular game.
Terry McIntyre <terrymcint...@yahoo.com> “We hang the petty thieves and appoint the great ones to public office.” -- Aesop ________________________________ From: Don Dailey <dailey....@gmail.com> To: computer-go <computer-go@computer-go.org> Sent: Sunday, July 12, 2009 3:40:10 PM Subject: Re: [computer-go] Re: Dynamic komi in commercial programs On Sun, Jul 12, 2009 at 1:22 PM, Christian Nentwich <christian.nentw...@gmail.com> wrote: >Don, others, > >>are there publications about this? If people have tried it out, are >>there any threads on this list that somebody remembers where results >>are posted? I have not been able to find any. It would be interesting >>to see. I think I just mentioned that there is probably not much on this except in the archive. And even then it's probably not very well documented. I did try this myself but I don't have any data to show what I did. What I remember is that it's incredibly tricky - how do you actually know when and how much to adjust? If the score starts getting really low or really high, do you restart the search with a new komi? If you restart then you have wasted effort. I tried 2 different thing. One of them involved using the total points won in some kind of hybrid approach and the other involved changing the komi during the game. Using JUST the total points won is a drastic weakening of the program and it's surprising how much. I tried factoring in a percentage of total points won and other things. After some time I gave up - it seemed like I was taking something that worked well and trying to make it better by factoring in something that sucked. It was like trying to make it play better by putting something in on purpose that I knew makes it play worse. The dynamic komi adjustment, from my recollection was more promising, but still played worse. The only way to make this work is if you know in advance what kind of position you really have. If you KNOW that you can pick off a small group without risk, then it probably would work just fine. But just increasing komi for no reason except that you are winning is not good enough. For instance if you KNOW there is a seki issue, then you should probably do it. But just doing it because there MIGHT be a seki issue every 50 games that actually matters is not good enough. You could call this a chicken and egg problem. You can of course easily construct positions that will illustrate how wonderful the idea is, and it will probably work great in those positions. Seki positions are always given as to why this will help - but not every game has a game critical seki. But I'm pretty convinced you cannot generalize the idea. You would have to do some kind of pre-analsysis to figure out what needs to be done, and by then you may already know what to do anyway and you have a more convential program. - Don > >>Christian > > > >>2009/7/12 Don Dailey <dailey....@gmail.com>: > >> >>> >>> On Sun, Jul 12, 2009 at 8:59 AM, Benjamin Teuber <benjamin.teu...@web.de> >>> wrote: >>>> >>>> > You just hit the nail on the head. Dynamic komi does not encourage a >>>> > program to overplay the position. Since you are starting from a losing >>>> > position you HAVE to overplay a bit. You have to attack when it is >>>> > futile. >>>> >>>> That depends on the komi - if you're behind by fourty points and set >>>> the virtual komi to 30, you play as if you'd be 10 behind, which would >>>> be agressive, but not kamikaze. >>>> >>>> This is exactly what people do, so I don't see your point. >>> >>> It's not up to me to prove anything. It's up to you. >>> >>> Several of us have tried variations of this idea of dynamic komi adjustment, >>> which seems like a very good premise. This SHOULD help the play. But the >>> fact of the matter is that none of us (so far) has made it work. If the >>> observations do not fit the premise, at some point we should actually >>> scrutinize the premise - even if the premise seems logical to us. >>> >>> I think the ones who still cling to this idea have not actually tried >>> implementing it. Have you tried? If you have, why are still talking >>> about it and not showing us something? >>> >>> >>> - Don >>> >>> >>> >>> >>>> >>>> >>>> Benjamin >>>> _______________________________________________ >>>> 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/ >
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