I haven't got a ladder example at the moment, but here's an instance where Leela does not realize it is in terrible trouble.
I ( with my 8 kyu AGA rating) know with certainty by move 223 (T5) that Black has captured a large white group. A stronger player could read this out sooner than I. This fight is too big to lose for either side; nothing else on the board matters. ( anyone? how early is this outcome pre-ordained? ) Based on the results of its analysis mode, Leela does not recognize the outcome of this semeai until the large white group in the bottom right is down to two liberties. The problem is even more stark in example2 -- similar board, black has foolishly played one of his own liberties for illustrative purposes. It is black's play, black has three liberties, white has three. Black must take away a liberty from white to win the capturing race, or make two eyes at T8. Black has only four playable moves; any other choice fails. Leela proposes - even after several minutes of analysis and a million nodes - that Black should tennuki at H14. That would snatch defeat from the jaws of certain victory; White would dive into T8 and win the race. I started this thread with the contention that analysis mode can help developers find problems, I hope this example explains why. My theory is that if a program could reliably recognize the outcome of such capturing races five or ten moves sooner, it could crush the likes of me. :D Terry McIntyre <terrymcint...@yahoo.com> "Government is an association of men who do violence to the rest of us." - Leo Tolstoy ________________________________ From: Michael Williams <michaelwilliam...@gmail.com> To: computer-go <computer-go@computer-go.org> Sent: Tuesday, April 21, 2009 1:57:54 PM Subject: Re: [computer-go] Reply to Lukasz and Don + Roadmap 2020 Mention the program so that the author can either refute your claim or fix the bug. terry mcintyre wrote: > Is it reasonable to expect pro players to use 6-dan programs as a tool for > analysis? The pro players are markedly better - at a rough guess, a pro > player could give a 6 dan amateur human or program a 3 stone handicap. > > On the other end of the scale, beginning players and mid kyu players could > indeed make good use of an analysis mode by a program which is better than > themselves. > > Lastly, an analysis mode would be helpful to developers, methinks. After > winning a game, I like to back up a few moves and find out when the program > realized that it was behind. This often happens several moves after the fatal > blow has already been struck. I know the feeling too well, when stronger > players deftly skewer my group and I only discover the problem five moves > later. What do they know that I don't? What do they know that the program > doesn't? > > We have a saying, you learn the most from reviewing games which you have > lost. An analysis mode can help developers to discover when their pride and > joy first begins to miss the target. > Lately, I have been playing quite a bit with a commercially available > program. An almost-ladder which has an extra liberty will apparently be > evaluated the same as a true ladder, and the program can be tricked into > trying to capture my ladder-like position. This sort of predictable flaw > might provide a clue to improve the next version. > > Terry McIntyre <terrymcint...@yahoo.com> > > "Government is an association of men who do violence to the rest of us." > - Leo Tolstoy > > > > ------------------------------------------------------------------------ > > _______________________________________________ > 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/
example.sgf
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example2.sgf
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