Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-17 Thread Magnus Persson
I use a method inititally from the Mogo team that sorts of randomizes the position before running the heavy playout. One simply plays uniformly random *non contact* moves. The effect of this is that it preserves the shapes of stones on the board, but it prevents the heavy playouts from

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-17 Thread Magnus Persson
I have to add that it is possible that a large part of the advantage from using heavy playouts in valkyria comes from using the same code to bias the the exploration part of MCTS. I could probably test it by simply relying completely on AMAF with the proximity heuristic as the only bias.

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-17 Thread Darren Cook
So you say that: ...I'm observing that most of the increase in level comes from the selection during exploration and only in small part from the selection during simulation., could you elaborate at all? This is very interesting. That almost suggests it might be fruitful to use the patterns

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Heikki Levanto
On Sat, Nov 15, 2008 at 11:38:34PM +0100, [EMAIL PROTECTED] wrote: Being a computer scientist but new to go, i can grasp some of the theory. The question I was trying to get across was: In a game of self play, if both parties are employing only monte carlo, surely its not a good conceptual

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread D Gilder
On Sunday 16 November 2008, Heikki Levanto wrote: On Sat, Nov 15, 2008 at 11:38:34PM +0100, [EMAIL PROTECTED] wrote: Being a computer scientist but new to go, i can grasp some of the theory. The question I was trying to get across was: In a game of self play, if both parties are employing

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Hideki Kato
Hello Heikki, Heikki Levanto: [EMAIL PROTECTED]: On Sat, Nov 15, 2008 at 11:38:34PM +0100, [EMAIL PROTECTED] wrote: Being a computer scientist but new to go, i can grasp some of the theory. The question I was trying to get across was: In a game of self play, if both parties are employing

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Heikki Levanto
On Sun, Nov 16, 2008 at 11:46:28AM +, D Gilder wrote: This is the way I understand the random playouts: If, in a given position, white is clearly ahead, he will win the game if both parts play perfect moves. He is also likely to win if both parts play reasonably good moves (say, like

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Magnus Persson
Quoting Hideki Kato [EMAIL PROTECTED]: Heikki Levanto: [EMAIL PROTECTED]: The way I understand it, modern Monte Carlo programs do not even try to emulate a human player with a random player - obviously that would not work. I believe CrazyStone's use of patterns does so and it seems

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Don Dailey
The random playouts or even heavy playouts are not intended to emulate a human player. Heikki is exactly right. It's a crude measurement of how good the position is. The moves in a random playout are horrible and so are the moves in a heavy playout. In fact, improving them arbitrarily

RE: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Magnus Persson
Yes, Valkyria does a lot of ladder reading as well. Actually pattern matching in the case of Valkyria is a little unclear, it is a decision trees where the leaves are often procedure calls that looks at a larger portion of the board. The ladder code is called for various reasons in the

RE: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread David Fotland
- From: [EMAIL PROTECTED] [mailto:computer-go- [EMAIL PROTECTED] On Behalf Of Magnus Persson Sent: Sunday, November 16, 2008 5:45 AM To: computer-go@computer-go.org Subject: Re: [computer-go] FW: computer-go] Monte carlo play? Quoting Hideki Kato [EMAIL PROTECTED]: Heikki Levanto

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Mark Boon
Some months ago I did several experiments with using tactics and patterns in playouts. Generally I found a big boost in strength using tactics. I also found a boost in strength using patterns but with a severe diminishing return after a certain number and even becoming detrimental when

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread George Dahl
So you say that: ...I'm observing that most of the increase in level comes from the selection during exploration and only in small part from the selection during simulation., could you elaborate at all? This is very interesting. That almost suggests it might be fruitful to use the patterns in the

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Mark Boon
On 17-nov-08, at 02:42, George Dahl wrote: So you say that: ...I'm observing that most of the increase in level comes from the selection during exploration and only in small part from the selection during simulation., could you elaborate at all? This is very interesting. That almost suggests

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread George Dahl
I look forward to hearing more! Happy testing. - George On Sun, Nov 16, 2008 at 11:53 PM, Mark Boon [EMAIL PROTECTED] wrote: On 17-nov-08, at 02:42, George Dahl wrote: So you say that: ...I'm observing that most of the increase in level comes from the selection during exploration and only

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-16 Thread Michael Williams
It seems move selection in the playouts should be very random at first and more deterministic toward the end of the playout. Has anyone tried that? Mark Boon wrote: On 17-nov-08, at 02:42, George Dahl wrote: So you say that: ...I'm observing that most of the increase in level comes from

Re: [computer-go] FW: computer-go] Monte carlo play?

2008-11-15 Thread Darren Cook
In a game of self play, if both parties are employing only monte carlo, ... random simulations... wouldnt it be very weak... ... and some playing around I am clearly mistaken because its works quite well. Yes, it doesn't make sense but it does indeed seem to work :-). I have seen papers