Re: [gnugo-devel] Re: [computer-go] SlugGo v.s. Many Faces

[David G Doshay]

On Aug 25, 2004, at 4:56 AM, Don Dailey wrote:

> > The primary reason  the code is so  very slow is that we  have found a
> > lookahead depth  of 16 works very well,  and it thus takes  a bit more
> > than 16 times as long as GNU Go to settle on its move.
>
> Can you  explain this statement?  You  make it sound  that your search
> takes linear time.  Would a 32 ply search take only twice as long?

At one limit the search time is linear in the plys because there is no 
branching
after the first set of candidate moves are selected. This is how we 
were running
in the reported games against Many Faces.

At the other limit it is still linear in the ply depth as long as there 
are cpus
available to supply the desired branching rate. We can do that too. We
have 72 cpus in our pool and intelligent use of them should result in 
stronger
play.

It is interesting that 16 moves of once-branched play is worth something
like 3 stones. We will continue to gather statistics to find out.

The infrastructure we are developing is designed to make it easy to 
program
simulations which make decisions at run time resulting in more cpus 
being
put to work. Go is our testbed application.

Thanks again to the GNU Go folks for supplying us with a code we barely 
had
to touch to do this.


Cheers,
David