On Fri, May 22, 2009 at 2:53 AM, Robert Jasiek <jas...@snafu.de> wrote:
> Don Dailey wrote: > >> 7x7 isn't solved by computer, but the best ones play it extrememly well. >> > > When looking through sample game trees of small board computer play, my > impression was that by far too many "trivial" moves were not analysed > (properly): single passes or seemingly bad plays. When I studied J1989 > manually, I had to learn that single passes or seemingly bad plays can be > good moves much more often than one fears. Therefore I am extremely > sceptical when some claim is made about NxN was "solved" by strong programs. > Usual strength is not a good measure here. Proofs or proof play are > appropriate. I haven't heard any claims yet by anyone that 7x7 has been solved. But 5x5 is claimed to have been solved by exhaustive search. And an admissible exhaustive search is a proof. Is the 5x5 claim the one you are skeptical about? Because I am not aware of any non-proof claims. In the case of 7x7 computer players, the practical play is very strong. I think you can construct positions that may be very difficult for computers to solve in 7x7, but from the opening position you are going to find it difficult to find a pathway that fools the computer - if you are on the wrong side of komi. When I did some experiments with Lazarus 2 or 3 years ago, I noticed that the overwhelming majority of games were one-sided when using any 1/2 point komi once you went beyond a reasonable level. As I cranked up the levels, the number of "upset" loses diminished and I found a level where there were no wins for the "wrong" side out of perhaps 200 games (don't remember the details.) I don't believe Lazaurs comes close to perfect play on 7x7 but I assume that the 7x7 opening position is relatively easy to win if you are on the correct side of komi. And it may be that the losing side also failed to take advantage of the mistakes of the winning side. So at 8.5 komi black always won, but this does not mean black always played the correct move. - Don > > -- > robert jasiek > > _______________________________________________ > computer-go mailing list > computer-go@computer-go.org > http://www.computer-go.org/mailman/listinfo/computer-go/ >
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