no. just don't prune the tree. or allow unpruning.
[email protected] wrote:
Following is a description of the nature and process of the UCT-MC method.
For a given Go board position P, let Np denote the total number of all
possble end of game positions. Let Ei denote each of the end of game
position (i=1,...,Np).
Let Mip denote all possible move sequences that starts from the position
P and ends at position Ei.
Assume the most simple MC simulation is used and there is no prunning at
all except the detection of the end of the game. Then the average of N
number of MC simulation gives the following ratio.
F=(sum of Mip where black wins)/(sum of all Mip)
Now the question is for F > 0.5 does it mean that P is a wnning position
for black? The anwser is not necessarily. Statistically for more than
50% of the cases it's true. This is the reason why the MC evaluation
works. It's also the reason why MC alone cannot be used to evaluate the
game. The reason above happens is that there exist narrow paths in the
game space. The searching part of the UCT-MC method is actually trying
to identify these narrow paths.
With the so called heavy playout the situationis a little dfferent. Here
the playout itself gets involved in the identifcation of the narrow paths.
In most of the cases the rules used in the heavy playout are not
perfect. This results in the incorrect prunning even in small number of
the cases. Generally the searching part of the UCT-MC method can
compensate for this error. However, one has to be carefull here, because
it's not guaranted. For example, it can hapen if the playout and the
searching part uses the same prunning rules. Could it be true that for
more powerful computers one should use lighter playout?
DL
------------------------------------------------------------------------
Check all of your email inboxes from anywhere on the web. Try the new
Email Toolbar now
<http://toolbar.aol.com/mail/download.html?ncid=txtlnkusdown00000027>!
------------------------------------------------------------------------
_______________________________________________
computer-go mailing list
[email protected]
http://www.computer-go.org/mailman/listinfo/computer-go/
_______________________________________________
computer-go mailing list
[email protected]
http://www.computer-go.org/mailman/listinfo/computer-go/
