Re: [computer-go] MC approach

2007-02-13 Thread Chris Fant
The following code did not hurt the strength against self-play in over 2000 games at boardsize 8x8 (faster games) with 10k playouts per move: moveEval[m] = (float)wins[m]/nGames[m] + points[m]/(nGames[m]*Board-Spaces*100) where points[m] is accumulated only for wins.

Re: [computer-go] MC approach

2007-02-13 Thread Weston Markham
On 2/9/07, Weston Markham [EMAIL PROTECTED] wrote: I don't seem to have any numbers on this anymore, but I should be able to try some experiments this weekend. I do have some code that does what I describe below. It is also using an all moves as first heuristic. According to my notes, I made

Re: [computer-go] MC approach

2007-02-12 Thread Weston Markham
I think that you are essentially correct. However, this is only going to affect a small number of games where two different moves are exactly tied for the best winning percentage, after many playouts. Even if the underlying probabilities are exactly the same, you can't really expect this to

Re: [computer-go] MC approach

2007-02-12 Thread Heikki Levanto
On Mon, Feb 12, 2007 at 11:20:43AM -0500, Weston Markham wrote: I think that you are essentially correct. However, this is only going to affect a small number of games where two different moves are exactly tied for the best winning percentage, after many playouts. Even if the underlying

Re: [computer-go] MC approach

2007-02-11 Thread Heikki Levanto
On Wed, Feb 07, 2007 at 02:41:22PM -0600, Nick Apperson wrote: If it only did one playout you would be right, but imagine the following cases: case 1: White wins by .5 x 100, Black wins by .5 x 100 case 2: White wins by 100.5 x 91, Black wins by .5 x 109 the method that takes into account

Re: [computer-go] MC approach

2007-02-09 Thread Weston Markham
I don't seem to have any numbers on this anymore, but I should be able to try some experiments this weekend. I do have some code that does what I describe below. It is also using an all moves as first heuristic. According to my notes, I made this change in an attempt to avoid severely

Re: [computer-go] MC approach

2007-02-08 Thread Magnus Persson
Quoting Heikki Levanto [EMAIL PROTECTED]: On Wed, Feb 07, 2007 at 04:42:01PM -0500, Don Dailey wrote: In truth the only thing that matters is to increase your winning percentage - not your score. There seems to be no point in tampering with this. I guess I must accept the wisdom of those

Re: [computer-go] MC approach

2007-02-08 Thread steve uurtamo
The average score can contain a very large proportion of losees if it is compensated by bigger wins. yes, it is easy to see how this might cripple the play of an MC player. that 90% territory win that requires 3 opponent blunders is tempting enough to ignore the fact that all other

Re: [computer-go] MC approach

2007-02-08 Thread Don Dailey
I think there are 15 first moves in 9x9 go if you factor out the symetries. UCT isn't good at evauating all the moves, it will pick one of them and spend most of it's time on it.But you could search each 1 at a time. The UCT programs are memory bound, so you could search each of these 15

Re: [computer-go] MC approach

2007-02-08 Thread Chris Fant
I thought that the memory boundedness was completely fixed by not expanding a UCT node until it has been visited X number of times. Just increase X until you are no longer memory bound. I don't recall anyone reporting a loss in playing strength by doing this. On 2/8/07, Don Dailey [EMAIL

Re: [computer-go] MC approach

2007-02-08 Thread Magnus Persson
Quoting Don Dailey [EMAIL PROTECTED]: I think there are 15 first moves in 9x9 go if you factor out the symetries. UCT isn't good at evauating all the moves, it will pick one of them and spend most of it's time on it.But you could search each 1 at a time. The UCT programs are memory bound,

Re: [computer-go] MC approach

2007-02-08 Thread Don Dailey
On Thu, 2007-02-08 at 08:59 -0500, Chris Fant wrote: I thought that the memory boundedness was completely fixed by not expanding a UCT node until it has been visited X number of times. Just increase X until you are no longer memory bound. I don't recall anyone reporting a loss in playing

Re: [computer-go] MC approach

2007-02-08 Thread Weston Markham
On 2/8/07, steve uurtamo [EMAIL PROTECTED] wrote: i wonder if this kind of greediness might, however, be useful for selecting, say, the first move or two in a 9x9 game. the thinking here is that since the endgame is essentially noise at this point, you might as well be greedy before tactics

Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC))

2007-02-07 Thread dhillismail
-Original Message- From: [EMAIL PROTECTED] To: computer-go@computer-go.org Sent: Wed, 7 Feb 2007 5:34 AM Subject: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC)) On Wed, Feb 07, 2007 at 12:06:40PM +0200, Tapani Raiko wrote: Let my try again using the

Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC))

2007-02-07 Thread dhillismail
I should have mentioned that I have only tested on 9x9. For larger boards, I don't know. - Dave Hillis ` Intuitively, it seems like this should work. You only give the winning margin a small weight, or only use it to break ties, or only apply it after the game

Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC))

2007-02-07 Thread terry mcintyre
If I recall correctly, someone spoke of constraining the opening moves to the 3rd,4th,and 5th lines in the absence of nearby stones, or something to that effect. What was the impact of this experiment? I notice the recent discussion of the need for a lot of thinking time to find good opening

Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC))

2007-02-07 Thread terry mcintyre
What sort of sampling was used for the playouts? For this variable ( incorporating some information about the score vs only the win-loss variable ), does it make a difference whether playouts are totally random or incorporate varying degrees of similitude to good play? From: [EMAIL PROTECTED]

Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC))

2007-02-07 Thread Richard J. Lorentz
terry mcintyre wrote: If I recall correctly, someone spoke of constraining the opening moves to the 3rd,4th,and 5th lines in the absence of nearby stones, or something to that effect. What was the impact of this experiment? For what it's worth, I tried a number of experiments along these

Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC))

2007-02-07 Thread dhillismail
Subject: Re: [computer-go] MC approach (was: Monte Carlo (MC) vs Quasi-Monte Carlo (QMC)) What sort of sampling was used for the playouts? For this variable ( incorporating some information about the score vs only the win-loss variable ), does it make a difference whether playouts are totally

Re: [computer-go] MC approach

2007-02-07 Thread Matt Gokey
Don Dailey wrote: On Wed, 2007-02-07 at 11:34 +0100, Heikki Levanto wrote: All this could be avoided by a simple rule: Instead of using +1 and -1 as the results, use +1000 and -1000, and add the final score to this. Heikki, I've tried ideas such as this in the past and it's quite

Re: [computer-go] MC approach

2007-02-07 Thread Nick Apperson
If it only did one playout you would be right, but imagine the following cases: case 1: White wins by .5 x 100, Black wins by .5 x 100 case 2: White wins by 100.5 x 91, Black wins by .5 x 109 the method that takes into account score would prefer the second case even though it has a lower

Re: [computer-go] MC approach

2007-02-07 Thread terry mcintyre
That drives me nuts! Minimax search would eliminate bad lines of play whenever a refutation is found. A good opponent would not play badly, and the quantity of possible bad moves should not affect the evaluation of good moves - but that seems to be what MC does, averaging out all moves

Re: [computer-go] MC approach

2007-02-07 Thread Don Dailey
On Wed, 2007-02-07 at 14:08 -0600, Matt Gokey wrote: Don, do you have any theories or information about why this is the case? Not really. In truth the only thing that matters is to increase your winning percentage - not your score. There seems to be no point in tampering with this. - Don

Re: [computer-go] MC approach

2007-02-07 Thread dhillismail
: Wed, 7 Feb 2007 4:31 PM Subject: Re: [computer-go] MC approach That drives me nuts! Minimax search would eliminate bad lines of play whenever a refutation is found. A good opponent would not play badly, and the quantity of possible bad moves should not affect the evaluation of good moves

Re: [computer-go] MC approach

2007-02-07 Thread Chris Fant
as often as good ones, so they don't contribute as much to the estimation of the worth of a node. - Dave Hillis -Original Message- From: [EMAIL PROTECTED] To: computer-go@computer-go.org Sent: Wed, 7 Feb 2007 4:31 PM Subject: Re: [computer-go] MC approach That drives me nuts

Re: [computer-go] MC approach

2007-02-07 Thread Heikki Levanto
On Wed, Feb 07, 2007 at 04:42:01PM -0500, Don Dailey wrote: In truth the only thing that matters is to increase your winning percentage - not your score. There seems to be no point in tampering with this. I guess I must accept the wisdom of those who have tried these things. Still, it hurts

Re: [computer-go] MC approach

2007-02-07 Thread Don Dailey
On Thu, 2007-02-08 at 00:46 +0100, Heikki Levanto wrote: On Wed, Feb 07, 2007 at 04:42:01PM -0500, Don Dailey wrote: In truth the only thing that matters is to increase your winning percentage - not your score. There seems to be no point in tampering with this. I guess I must accept

Re: [computer-go] MC approach

2007-02-07 Thread Weston Markham
But of course, it's not the size of the win that counts, it is rather the confidence that it really is a win. In random playouts that continue from a position from a close game, the ones that result in a large victory are generally only ones where the opponent made a severe blunder. (Put

Re: [computer-go] MC approach

2007-02-07 Thread Hideki Kato
Matt Gokey: [EMAIL PROTECTED]: Weston Markham wrote: But of course, it's not the size of the win that counts, it is rather the confidence that it really is a win. Yes, and my reasoning was that a larger average win implied a higher confidence since there is more room for error. That intuition