Re: [computer-go] The global search myth

2007-12-05 Thread Álvaro Begué
A long time ago I thought of how to organize what to prune The Right Way (tm). I initially thought about it in the context of computer chess, but I think it is even more relevant for computer go. Instead of doing global search where you say a node will be considered a leaf if it is n moves away

Re: [computer-go] The global search myth

2007-12-05 Thread Álvaro Begué
On Dec 5, 2007 9:33 AM, Erik van der Werf [EMAIL PROTECTED] wrote: Look for Realization Probability Search. Oh, thanks! I knew it was too natural to be original. Well, I actually thought about it around 1998, so it might have been new back then. This is very close to what I was saying:

Re: [computer-go] The global search myth

2007-12-05 Thread Álvaro Begué
On Dec 5, 2007 1:35 PM, Don Dailey [EMAIL PROTECTED] wrote: Yes, I think there is a lot to this.Searching by depth is rather arbitrary. I think this basic idea is called realization probabilities and I thought of doing it with the Bradley Terry model. It also occurred to me that if a

Re: [computer-go] The global search myth

2007-12-05 Thread Erik van der Werf
On Dec 5, 2007 5:01 PM, Álvaro Begué [EMAIL PROTECTED] wrote: On Dec 5, 2007 9:33 AM, Erik van der Werf [EMAIL PROTECTED] wrote: Look for Realization Probability Search. Oh, thanks! I knew it was too natural to be original. Well, I actually thought about it around 1998, so it might have

Re: [computer-go] The global search myth

2007-12-05 Thread Álvaro Begué
On Dec 5, 2007 11:33 AM, Erik van der Werf [EMAIL PROTECTED] wrote: On Dec 5, 2007 5:01 PM, Álvaro Begué [EMAIL PROTECTED] wrote: On Dec 5, 2007 9:33 AM, Erik van der Werf [EMAIL PROTECTED] wrote: Look for Realization Probability Search. Oh, thanks! I knew it was too natural to be

Re: [computer-go] The global search myth

2007-12-04 Thread Álvaro Begué
On Dec 4, 2007 1:42 AM, Petri Pitkanen [EMAIL PROTECTED] wrote: There is something that the latest Monte Carlo programs have in common with the best chess programs - and seems to be the right way to structure a game tree search.Your selectivity should be progressive. In order to

Re: [computer-go] The global search myth

2007-12-04 Thread Forrest Curo
Relatively speaking chess eval of adding piece values together and doing nothing else is far closer to optimal evaluation function that what is currently available in Go. A GOOD go evaluation function probably needs to incorporate lookahead... Through most of the game, the difference between a

Re: [computer-go] The global search myth

2007-12-03 Thread Don Dailey
David Doshay wrote: On 22, Nov 2007, at 9:35 AM, Don Dailey wrote: This is one of many things in life that people refuse to believe - regardless of the evidence. ... Instead, people focused on highly selective searches. In order to play strong it was clear that computers would have to

Re: [computer-go] The global search myth

2007-12-03 Thread David Doshay
Yes, in its present instantiation, SlugGo is inadmissibly selective. In this case, we clearly see that after some small number, more plies of global search result in worse play. I do not have any expectation of perfect play, only improvement over the present state of things. Cheers, David On

Re: [computer-go] The global search myth

2007-12-03 Thread Petri Pitkanen
There is something that the latest Monte Carlo programs have in common with the best chess programs - and seems to be the right way to structure a game tree search.Your selectivity should be progressive. In order to do this correctly you must re-visit nodes many times. Chess programs

[computer-go] The global search myth

2007-11-22 Thread Don Dailey
Instead of responding individually, I would like to address a myth in one message.The myth is that any kind of global search, whether it be alpha/beta, or the currently explored best first search methods is a foolish approach and that there is a some kind of constant time elegant algorithm

Re: [computer-go] The global search myth

2007-11-22 Thread steve uurtamo
it's in EXPTIME, with boardsize as the parameter. s. - Original Message From: Don Dailey [EMAIL PROTECTED] To: computer-go computer-go@computer-go.org Sent: Thursday, November 22, 2007 12:35:37 PM Subject: [computer-go] The global search myth Instead of responding individually, I

Re: [computer-go] The global search myth

2007-11-22 Thread steve uurtamo
it's PSPACE-hard and EXPTIME-complete, although this is dependent upon the rules involved. i think that superko changes things a tiny bit. in any case, it's brutally difficult as the boardsize increases. JM Robson, The Complexity of Go. In Information Processing; proceedings of IFIP

Re: [computer-go] The global search myth

2007-11-22 Thread steve uurtamo
Subject: Re: [computer-go] The global search myth it's PSPACE-hard and EXPTIME-complete, although this is dependent upon the rules involved. i think that superko changes things a tiny bit. in any case, it's brutally difficult as the boardsize increases. JM Robson, The Complexity of Go

Re: [computer-go] The global search myth

2007-11-22 Thread Matthew Woodcraft
Don Dailey wrote: Back then the ELO curve was not understood. The basic formula was eventually found that 1 ply added 250 ELO rating points to a program. [...] At some point, some incredibly foolish programmers at Northwestern University built a program and decided that it was too hard to do

Re: [computer-go] The global search myth

2007-11-22 Thread Don Dailey
Can you elaborate on the relation between the 'ELO curve' and the improved evaluation functions? Is it that if you took this original 'brute force' program and ran it on current hardware, it would gain 250 rating points per ply, and the improved evaluation functions allow modern programs to