I guess I'm not really appreciating the difference between node value
prior and progressive bias - adding a fixed small number of wins or
diminishing heuristic value seems very similar to me in practice. Is the
difference noticeable?
On Tue, Sep 29, 2009 at 08:25:56AM -0700, David Fotland wrote:
> I start with one move, and slowly add moves to the pool of moves to be
> considered, peaking at considering 30 moves.
>
> My current schedule looks like:
>
> visits 0 2 5 9 15 24 38
> 59
> 90 100 ... 2142
> moves 1 2 3 4 5 6 7 8
> 9 10 ... 20
>
Thanks!
On Tue, Sep 29, 2009 at 08:49:22PM +0200, Olivier Teytaud wrote:
> I don't know to which extent my terminology is commonly used, but it seems
> to be close to the distinction by Dave (but not exactly equal).
>
> For me I use "progressive widening" when we add moves, progressively,
> to the pool of moves which are to be considered;
>
> whereas I use "progressive unpruning" when a score is computed for all
> moves, with a weight depending on the number of simulations; typically, I
> consider the Rave formula in Gelly&Silver as a progressive unpruning (with,
> for "prior" value, the Rave value).
Ah, I see; so "progressive widening" is what David described, modifying
the process of choosing node with highest urgency, while what you describe
as "progressive unpruning" is actually "just" what RAVE and priors are,
adding extra terms to the urgency calculation, with diminishing value as
the simulation count raises.
> * with progressive unpruning, if your prior is bad, you might have
> situations
> in which the score of the only good move is 0, whereas all bad moves have
>
> values going to 0 but >0 and therefore the good move is never simulated
> (this can, however, easily be patched by a lower bound on the value given
> by the prior)
I found the "even game prior" (3/6) effective for this problem.
> Progressive unpruning, if you use the same terminology as me, has the
> advantage that the number of moves to be considered is adapted depending on
> the score; if you have three reasonnable moves and 300 bad moves, with
> progressive unpruning you'll visit all moves, whereas progressive unpruning
* progressive widening you'll?
> will stay on the three reasonnable moves as long as they provide a better
> score than the prior score for the 300 bad moves.
--
Petr "Pasky" Baudis
A lot of people have my books on their bookshelves.
That's the problem, they need to read them. -- Don Knuth
_______________________________________________
computer-go mailing list
computer-go@computer-go.org
http://www.computer-go.org/mailman/listinfo/computer-go/
