This is an artifact of using mercy rule. You can change it in config.cpp use_mercy_rule = true
Should I make it default? Thanks, Lukasz On Dec 10, 2007 11:41 PM, Heikki Levanto <[EMAIL PROTECTED]> wrote: > On Mon, Dec 10, 2007 at 04:08:48PM -0500, Don Dailey wrote: > > Would you rather be 95% confident of a win or 90% confident? There is > > only 1 correct answer to that question. > > Yes, if you can offer me reliable confidence numbers. We all (should) know > that MC evaluations suffer from systematic problems that can not just be > averaged away statistically. > > Compare these two positions: > > playout_benchmark 10000 > = Initial board: > komi 7.5 > A B C D E F G H J > 9 . . . . . O O O O 9 > 8 O O O O O O O O O 8 > 7 O O O O O O O O O 7 > 6 O O O O O O O O O 6 > 5 # # # # # # # # # 5 > 4 O O O # # # # # # 4 > 3 O O O O . # # # # 3 > 2 . O O O . # # # . 2 > 1 # . O O . # # . # 1 > A B C D E F G H J > Performance: > 10000 playouts > 0.032002 seconds > 312.481 kpps > Black wins = 1937 > White wins = 8063 > P(black win) = 0.1937 > > > playout_benchmark 10000 > = Initial board: > komi 7.5 > A B C D E F G H J > 9 . # . . . O O O O 9 > 8 O O O O O O O O O 8 > 7 O O O O O O O O O 7 > 6 O O O O O O # # # 6 > 5 # # # # # # # # # 5 > 4 O O O # # # # # # 4 > 3 O O O O . # # # # 3 > 2 . O O O . # # # . 2 > 1 . . O O . # # . # 1 > A B C D E F G H J > Performance: > 10000 playouts > 0.084006 seconds > 119.039 kpps > Black wins = 7746 > White wins = 2254 > P(black win) = 0.7746 > > > Which one is better, 77% or 19%? > > > I must admit I don't quite understand the results myself. But they are made > with LibEGOs MC, so I trust they show what traditional MC simulation would > see. The top group is "obviously" alive but can die in a MC simulation. The > bottom group is "obviously" unsettled, so who ever plays there first should > win the game. I suppose in some follow-ups, white may be able to live in the > resulting space, and win the game that way too. > > This has nothing to do with the argument of attacking the larger group first, > rather the contrary. But it shows that MC evaluations can give results so > badly off that there is not always much point in distinguishing between your > 80% and 85% confidence. > > Regards > > Heikki > > -- > Heikki Levanto "In Murphy We Turst" heikki (at) lsd (dot) dk > > > _______________________________________________ > 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/
