[computer-go] MoGo/professional challenge

[Olivier Teytaud]

For information on the mogo/pro challenge:
- during preliminary tests, mogo has won 4/0 against a very high level
   human; at that time we were just very very very happy :-)
- some other humans, supposed to be weaker, have however
   won some games at that time (before the nakade correction);
- the Nakade weakness is currently assumed to be solved, but I'm not sure
   of that - at least mogo solves the "old" known nakade situations and is
   stronger than the old mogo; at that time we were happy again :-)
- another improvement is that we currently have access to much
   hardware than during tests above;
- but, a human, supposed to be weaker (non professional level, 5Dan
   however) has found some trick to win against mogo; this is not the
   nakade, but this is seemingly stable, and I am just not able of
   explaining how he can do that; he has shown me situations and says that
   "in this kind of situations, mogo makes an error", but I just don't
   understand the common point in these situations. If we understand
   something we will post details here (at least the sgf files)...
- in 9x9, the MPI (multi-machine) version of mogo wins with probability
   80% against the non-MPI version. The speed-up is better in 19x19 and
   will be detailed later, after extensive experiments - the focus was
   on 9x9 until now due to the challenge.
- once again, very strong improvements in front of old versions of mogo
   leads to disappointing improvements against humans. However, I think
   that the best 9x9 go programs (mogo and others) are currently difficult
   opponents for high level players.

Everything is under writing for publication and will be sent on this 
mailing list.
Some technical details:
- due to concurrency in memory access, heavier playouts come for free. If
   playouts are heavier (computationally more expensive) the speed-up
   becomes better. The nakade-problem involves heavier playouts, but the
   computational overhead is almost canceled by the speed-up improvement,
   as the speed-limit on 8-core machine is due to concurrency in memory
   access (for modifying the tree) more than to computational cost.
- (very) unfortunately, the opening books generated for mogo without
   nakade are seemingly poor for mogo with nakade... this has destroyed
   weeks of work.

If mogo wins the challenge, I'd like to point out that this is a 
collective success of the computer-go mailing list - without gnugo, 
crazystone, cgos, kgs and so on, mogo would just not exist. Thanks to all 
of you for that. I regret that due to some restrictions,
we have not published every detail before, but it was just a 
matter of weeks and I'm happy that everything will be published soon, and 
if we loose the challenge I hope someone else will win something similar 
soon :-)
Olivier