On Thu, 2006-11-30 at 18:40 -0800, David Fotland wrote:
> How does monte carlo go do with fights that are trivial to evaluate, but
> hard to search?
It's easy to construct problems that any program cannot handle including
yours.
You have to understand that Monte Carlo is not great at tactics, it's
search is a kind of meta-search designed to understand the general
course of the game. It's ok at basic tactics but that is not it's
forte. (Although I believe programs like Mogo have gone a long way
towards correcting this type of weakness.)
I've watched a lot of games between my own weak monte carlo program and
gnugo - and sometimes it loses to tactics. But other times it makes
gnugo look stupid, as if it just layed down and died. And it's
because my program actually understood the position better. If it gets
into a fight that requires careful accurate calculation, gnugo is
better because it does more searching.
> The attached position (I think from Martin Mueller), has many such fights.
> If your program can count liberties correctly, it is easy to evaluate and
> choose the best move with 1 ply lookahead.
> If you try to do a full board
> search for the best move it will take 50 ply or more. This position has a
> large number of big fights where the side to move wins the local fight.
>
> I think smart evaluation beats dumb search, monte carlo or otherwise.
I believe this is a meaningless statement because evaluation is the only
important thing - that part is well understood. Search is just a way to
gain knowledge and knowledge is what we are lacking and we all agree on
this. In fact search IS evaluation.
I can't understand why people think a program has to either search or
evaluate. The only thing any program does is evaluate and that's all
there is. I used to call my search routine eval() because that's all
it is.
I know you understand this too - I think you are just trying to pick a
fight. Your program has a global search and local searches presumably
because it helps your program evaluate positions right?
My position is that knowledge engineering is at a steep point of
diminishing returns. How much improvement do you think you will gain
with a few more years of adding more patterns? Are you expecting
major breakthroughs which will allow you to reduce the searching that
you do now?
Intuitively it's easy to criticize how stupid the programs are and come
to the simple conclusion that they need to understand a lot more - and
rightly conclude that this will make them much better - but apparently
this is incredibly difficult. There is no breakthrough that promises
to substantially improve this situation with static evaluation. I
don't think a few more patterns is going to cut it either. The answer
will have to be more sophisticated evaluation and that means you will
have to slow your evaluation down substantially by using recursion - a
search. There is no law against trying to apply knowledge to the
search either and is what has been happening in computer chess for
years. Almost all the breakthroughs have been about being smarter and
most of them have been about being smarter about what you search.
At some point you won't be able to pack much more static knowledge into
your program if you refuse to think about what the opponent can do, how
you might respond, etc. There is nothing "dumb" about this.
- Don
> David
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED] On Behalf Of David Doshay
> > Sent: Thursday, November 30, 2006 3:49 PM
> > To: computer-go
> > Subject: Re: [computer-go] Monte-Carlo is the future of 19x19
> >
> >
> > I think that MC will be useful on 19x19 if a clever way to restrict
> > it to
> > sub-game searches can be implemented.
> >
> > Cheers,
> > David
> >
> >
> >
> > On 30, Nov 2006, at 1:51 PM, Rémi Coulom wrote:
> >
> > > Chrilly wrote:
> > >>>
> > >>> I believe that MC will be the only way to write a GO
> > program in the
> > >>> near future leaving the other stuff in the dust (like Mogo has
> > >>> with 9x9
> > >>> Monte Carlo Go.) This happened in computer chess several times,
> > >>> someone came up with some breakthrough idea, proved it
> > with actual
> > >>> results and everyone else had to play follow the leader
> > to catch up.
> > >>>
> > >> Do you think its also the future of 19x19 or only of 9x9 (maybe
> > >> 13x13)?
> > >>
> > >> Chrilly
> > >>
> > >> _______________________________________________
> > >> computer-go mailing list
> > >> computer-go@computer-go.org
> > >> http://www.computer-go.org/mailman/listinfo/computer-go/
> > > I am certain it is for 19x19. Just look at the KGS games of Mogo on
> > > 19x19. I played one game against it, and won. I got the feeling it
> > > was slightly easier to beat than GNU Go, but that may be because I
> > > am used to the way Monte-Carlo programs play. I predict
> > that in one
> > > year or two, classical programs will be far behind MC programs on
> > > 19x19. Maybe it will take less than one year.
> > >
> > > Rémi
> > > _______________________________________________
> > > computer-go mailing list
> > > computer-go@computer-go.org
> > > http://www.computer-go.org/mailman/listinfo/computer-go/
> >
> > _______________________________________________
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