Hello,

I answer here on the discussion because I think it is more relevant to what
I wanted to say. Sorry not to answer to the lasts posts.


The computer go guys don't think of performance as a function of time,
only as a kind of absolute, it plays good or it doesn't.


I think it simply comes from the fact that the majority of strong Go
programs do not scale well (do not improve a lot) with the thinking time.
This is a fact, so the experiments done by Hiroshi are totally relevant,
even if the programs did not take the same amont of time. With more time I
bet the results would have been very close.

Comparing to chess, I think also that we experiment  19x19 computer Go in
blitz games. I used to play chess, and 20 minutes games was called
semi-blitz. 19x19 Go has a lot more moves to do, so for me 30 minutes games
are blitz. I set up MoGo playing in 30 minutes for 19x19 in KGS. I think
people would simply not play if the games were longer.
So GnuGo and commercial programs have been optimized to play strong in very
few time. For them, long thinking time is simply not relevant. It is not the
same goal.

The scale of MoGo in 19x19 with the thinking time is very different (against
gnugo 3.7.10 level 8):
- with 35000 simulations/move (~30seconds/move in a P4 3.0Ghz) the winning
rate is 39%
- with 70000 it becomes 59%
My preliminary experiments before the slow tournaments showed very high
winning rates with high thinking time, and at this time the 70000
simulations winning rate was closer to 30%.

So it depends on what your goals are? Playing strong very fast (gnugo is
incredibely good at that, mogo will play random)? Playing strong with a big
computer power (UCT approaches scale better)?
For commercial programs and also GnuGo, the first goal is clearly better, so
comparison with more thinking time would not be fair.
For computer science perspective, the second goal seems more appealing, so
comparison with less thinking time would not be fair.


Sylvain
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