zen builds sekis, and occasionally wins games that way. s.
On Tue, Jun 30, 2009 at 1:25 PM, Jason House<jason.james.ho...@gmail.com> wrote: > Is it possible to explicitly use a monospace font? I can't read your board > positions. > > I haven't heard of any handling of seki in playouts except for Remi's > CrazyStone. I don't think he's ever given specifics on how he did it. Maybe > he'll respond to your e-mail? > > Sent from my iPhone > > On Jun 26, 2009, at 1:37 PM, "Brian Sheppard" <sheppar...@aol.com> wrote: > >> Here is a position that exposed some bugs in Pebbles. Maybe it will help >> you. >> >> 1 2 3 4 5 6 7 8 9 >> A - O - O X - - X - >> B - X O - O X - O O >> C - O O - O - X O - >> D X X X O O O O O O >> E - O X X X O X O O >> F - - O X O X X X X >> G - - X X O O X X - >> H - O X O - O O X X >> J - O X O O - X - X >> X to play. >> >> X is already doomed in this position. The bottom O group is in a seki >> with the X group at right. O cannot play J6 self-atari. X cannot fill >> in J8 and then play J6, and after X J6, O captures and X cannot recapture. >> So it will be dual life. Because the top of the board is O's, O have >> more than half the board, even without komi. >> >> The playouts have to handle certain issues well in order to find that. >> The first point is to filter out plays that make self-atari on large >> groups. This will cause the rest of the board to fill up until only >> the seki remains. >> >> The the playout will be in a position like the following: >> >> 1 2 3 4 5 6 7 8 9 >> A - O - O O - O O - >> B O - O - O O - O O >> C - O O - O - O O - >> D X X X O O O O O O >> E - X X X X O X O O >> F X X - X O X X X X >> G X - X X O O X X - >> H X X X O - O O X X >> J X - X O O - X - X >> X to play. >> >> Pebbles does not detect superko in playouts, so this position will loop >> forever with J6/J8/J7/pass. In Pebbles, infinite games were scored as >> draws. I changed that to give the win to O on the basis of its >> preponderance >> of material. (No doubt that will bite me at some point.) >> >> Even if we detect the superko repetition, it seems to me that we are only >> getting the right answer by accident. For instance, if X plays J6 then >> after J8/J7 there is no move for X, so X has self-ataried himself. >> >> Another possibility if to see that X's J6 is atari and also self-atari, so >> X can look for the approach move. In this case X would play J8 instead of >> J6 >> which avoids the ko. Then the seki is obvious. >> >> How do other programs handle this case? >> >> _______________________________________________ >> 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/
