[Computer-go] How well does pure monte carlo play?

[Petr Baudis]

On Sat, Jan 21, 2012 at 03:42:57PM -0500, Don Dailey wrote:
> On Sat, Jan 21, 2012 at 2:31 PM, Eric Baum <ebaum at fastmail.fm> wrote:
> 
> > If you don't do rave, or use patterns to predict likely moves, or any of
> > that, but just do pure monte carlo,
> > parallelized on a cluster,how well would that play Go? Anyone know?

Given enough memory and thinking time, like a pro. ;-) Too general
question.

> If you are talking about a pure light playout without patterns but still
> using a very basic MC tree implementation,   it will play very poorly
> compared to the best stuff we have.   But it would still be better than
> what we had before MCTS.    It might reach the 1D level assuming a good
> parallel cluster implementation.

I assume you are talking about 9x9? A rather optimistic estimate would
be 1600 Elo on CGOS for 50k playouts per move; with GNUGo at 1800 Elo,
we could estimate this as 8k KGS. So about 12.8 million playouts per
move assuming ideal scaling (100 Elo per doubling, again optimistic)
in order to gain 800 Elo from there. I wonder what it would take in
practice.

I could never get non-RAVE MCTS to play above ~20k strength on 19x19
(not that I tried hard).

				Petr "Pasky" Baudis