Re: [computer-go] a ladder example
terry mcintyre wrote: I promised an example of a monte carlo program mistakenly starting a ladder; here it is. I played white; Leela had a 2 stone handicap and 45 minutes on the clock. Leela's move 32 initiates a ladder. Unfortunately for Leela, I have a ladder breaker at D16. Leela's analysis was optimistic when it initiated the ladder, but a few moves later, it became aware of the looming shadow of a great doom. Leela reads out ladders, so I'm quite surprised to see this. I suspect the problem is that it overestimates it's chances to kill your group in the aftermath of the ladder, which doesn't directly have anything to do with the ladder itself. -- GCP ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
[computer-go] a ladder example
I promised an example of a monte carlo program mistakenly starting a ladder; here it is. I played white; Leela had a 2 stone handicap and 45 minutes on the clock. Leela's move 32 initiates a ladder. Unfortunately for Leela, I have a ladder breaker at D16. Leela's analysis was optimistic when it initiated the ladder, but a few moves later, it became aware of the looming shadow of a great doom. There are a few large captures later in the game. The corner fight at the end had me biting my nails. Terry McIntyre terrymcint...@yahoo.com Here you can see how slightly a people needs to be governed. - Carl Schurz, immigrant, 1848. What happened since? score_me.sgf Description: Binary data ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
RE: [computer-go] a ladder example
I think all uct/mc programs will have this problem unless they add something extra to avoid it. During playouts using random moves the playouts will think that the ladder usually works. Local 3x3 patterns aren't enough since they can't tell the difference between ladders that work and ladders that don't work. Some programs read ladders during playouts so they know the local result and can play correctly. Many Faces doesn't read ladders during playouts, since I think it's too slow, but I found a different solution to the problem. Mogo and Crazystone must some solution to this problem, but I don't know what it is. This should only show up for long ladders, since the UCT tree part of the search will read a ladder correctly. David From: computer-go-boun...@computer-go.org [mailto:computer-go-boun...@computer-go.org] On Behalf Of terry mcintyre Sent: Saturday, May 02, 2009 9:49 AM To: computer go Subject: [computer-go] a ladder example I promised an example of a monte carlo program mistakenly starting a ladder; here it is. I played white; Leela had a 2 stone handicap and 45 minutes on the clock. Leela's move 32 initiates a ladder. Unfortunately for Leela, I have a ladder breaker at D16. Leela's analysis was optimistic when it initiated the ladder, but a few moves later, it became aware of the looming shadow of a great doom. There are a few large captures later in the game. The corner fight at the end had me biting my nails. Terry McIntyre terrymcint...@yahoo.com Here you can see how slightly a people needs to be governed. - Carl Schurz, immigrant, 1848. What happened since? ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
Re: [computer-go] a ladder example
Is it practical to recognize the initiation of a ladder, and expand the nodes all the way to the end, to determine whether it works or not? More generally speaking, if a large group can be repeatedly put into atari, the outcome will usually swing the game one way or the other. One of the players pursuing a ladder has usually made a fatal error; Hugh Grant Important to know. Terry McIntyre terrymcint...@yahoo.com Here you can see how slightly a people needs to be governed. - Carl Schurz, immigrant, 1848. What happened since? From: David Fotland fotl...@smart-games.com To: computer-go computer-go@computer-go.org Sent: Saturday, May 2, 2009 11:35:36 AM Subject: RE: [computer-go] a ladder example I think all uct/mc programs will have this problem unless they add something extra to avoid it. During playouts using random moves the playouts will think that the ladder usually works. Local 3x3 patterns aren’t enough since they can’t tell the difference between ladders that work and ladders that don’t work. Some programs read ladders during playouts so they know the local result and can play correctly. Many Faces doesn’t read ladders during playouts, since I think it’s too slow, but I found a different solution to the problem. Mogo and Crazystone must some solution to this problem, but I don’t know what it is. This should only show up for long ladders, since the UCT tree part of the search will read a ladder correctly. David From:computer-go-boun...@computer-go.org [mailto:computer-go-boun...@computer-go.org] On Behalf Of terry mcintyre Sent: Saturday, May 02, 2009 9:49 AM To: computer go Subject: [computer-go] a ladder example I promised an example of a monte carlo program mistakenly starting a ladder; here it is. I played white; Leela had a 2 stone handicap and 45 minutes on the clock. Leela's move 32 initiates a ladder. Unfortunately for Leela, I have a ladder breaker at D16. Leela's analysis was optimistic when it initiated the ladder, but a few moves later, it became aware of the looming shadow of a great doom. There are a few large captures later in the game. The corner fight at the end had me biting my nails. Terry McIntyre terrymcint...@yahoo.com Here you can see how slightly a people needs to be governed. - Carl Schurz, immigrant, 1848. What happened since? ___ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
