[computer-go] Monte-Carlo Go Misnomer?

[dhillismail at netscape.net]

     I agree with what you say here and I'll try to make my point better. First, my limited experience working with Monte-Carlo simulations involved photons traveling through scattering media. The sequences of moves described in the Mogo paper are pleasantly reminiscent of this. 
 
     I did not mean to suggest that heavy playouts, incorporating go knowledge, makes the Monte-Carlo description incorrect. Rather, the term is increasingly insufficient as a Go engine description because it lumps together such very different algorithms. The earliest MC engines were extremely simple and easily described. It seems inevitable that someone new to the field will seize on this description, and then combine it with the success of current Monte-Carlo engines, leading to unnecessary confusion.
 
     On a tangential note: MC/UCT with light playouts and MC/UCT with heavy playouts are different beasts. If SlugGo's mixture of experts work expands to include MC/UCT, you might want to consider adding one of each.
 
- Dave Hillis
 
-----Original Message-----
From: ddoshay at mac.com
To: computer-go at computer-go.org
Sent: Fri, 2 Feb 2007 12:30 AM
Subject: Re: [computer-go] Monte-Carlo Go Misnomer?


I am a physics guy, and my thesis project was a large MC simulation. The clusters that run SlugGo are usually busy doing MC simulations when not playing Go. 
 
In general MC needs to sample according to the proper distribution for the problem. For some problems in quantum mechanics and most in statistical mechanics, the distribution cleanly partitions into percentages of the total, and in those simulations it is easy to do things like generate random numbers and then see what range the random number is in. For Go I could easily argue that sampling random points on the board is clearly the wrong distribution, and those programs using some kind of pattern knowledge are really doing something much closer to MC simulations rather than true random playout. So, I do not think that MC is the misnomer. Thinking that pure random playout is the same as MC is the mistake. 
 
Cheers, 
David 
 
 
On 1, Feb 2007, at 8:33 PM, dhillismail at netscape.net wrote: 
 
> 
> I think of it as a continuum going from "light" to "heavy." > Pure random playouts are the lightest. But then you add some rules > about filling in eyes, then maybe discourage self-atari,... and the > playouts keep getting heavier. I agree with you that the current > crop of MC engines are not nearly as go-knowledge naive as the name > implies. 
> 
> - Dave Hillis 
> 
> -----Original Message----- 
> From: mgokey at charter.net 
> To: computer-go at computer-go.org 
> Sent: Thu, 1 Feb 2007 11:22 PM 
> Subject: [computer-go] Monte-Carlo Go Misnomer? 
> 
> Is MC Go a misnomer for programs in this genre not using simple random 
> playouts and combining with other techniques like pattern matching? 
> 
> Technically, does the general Monte-Carlo method require random or 
> pseudo-random sampling? 
> 
> If so, should we dub a new name for these non-random deep play-out 
> sampling based go programs? Maybe Quasi-MC or Directed 
> Sampling... 
> 
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