On Wed, 2008-09-24 at 15:17 +0200, "Ingo Althöfer" wrote:
> Don Dailey wrote:
> > I think a better way to do this is to self-play a few hundred games with
> > various komi values.   
> Do you mean HUMAN self-play or COMPUTER self-/auto-play?
> When you mean human self-play, I am not sure that
> this is a safer way for such small boards.

I am talking about computer self-play on small boards - I think it gives
a very reliable way to determine komi (on small boards.)   It's of
course not a proof, just as your method is not a proof.

Somewhere in the archives I posted data based on a lot of games at 7x7
using 9.5 and 8.5 komi.   I used Lazarus,  not a particularly strong
program, but not a weak program either (about 2200 ELO on CGOS.)  

I don't have the numbers in front of me, but it was ridiculously
one-sided.  I did not have to set Lazarus to a very high level in order
to get almost 100% win results with white using 9.5 komi.

When I went to 8.5 komi,  Black wins almost every single game.  My
empirical conclusion is that the correct komi is probably 9.0 for the
7x7 board size.

This method I propose doesn't give a proof.  However, you can improve
your confidence like this:

Play (let's say) 1000 games for each komi we are testing, then do a
statistical analysis of the results.   If for instance it looks like
black wins 98% of the games with some komi,  we could take a look at the
2% he lost and try to determine if black just made a stupid move,  or
white happened to find a very difficult move which actually leads to a
win regardless of black does.    If there is some evidence that white
found a very difficult move which changes things,  we could do a further
analysis based on the same methodology, but from this new starting

I would like to do this test but Lazarus doesn't support even size
boards (although I might be able to fix this without a lot of trouble)
and I don't have a copy of Leela although I might convince Gian Carlo to
send me a copy.    I'm not sure what mogo supports.  

> > The correct komi will be clear from those games.
> > This worked on 7x7 
> Are such 7x7-games documented somewhere, for
> instance in the internet?

Yes, I posted my results some time ago.  This may go back a couple of
years or more.   I will look for it.

> > so I assume it would work on 6x6.   Of course this
> > cannot be considered a "proof."
> Right. 
> What I did is a computer-aided (incomplete) analysis:
> running repeated Monte-Carlo searches where the komis
> for both sides differ by 1.

I don't know if even size boards are special, but it seems to me that
such small boards should have very high komi's.   4.0 seems pretty low
but then I'm really no expert on komi's and I'm a pretty weak player so
I'm not in any position to really say.

- Don

> Ingo.

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