[computer-go] Re: Should 9x9 komi be 8.0 ?]

[Jonas Kahn]

>  From my observaion, mc chooses good moves if and only if the winning 
> rate is near 50%.  Once it gets loosing, it plays bad moves.  Surely 
> it's an illusion but it helps to prevent them.

If it's more important to avoid being too pessimistic (ie low estimated
winning rates), there are two ways to bias the formulas below:
either you use a bigger lambda when the estmated true winning rate is
less than .5
or you replace .5 by .55 everywhere.

> >new_komi_aya =
> >    truncation[(.5 - old_winning_rate) +
> >    C * old_komi_aya - lambda / (2 * C)]^{+}
> >
> >if the estimated winning rate with true komi is more than .5, and
> >
> >new_komi_aya =
> >    truncation[(.5 - old_winning_rate) +
> >    C * old_komi_aya + lambda / (2 * C)]^{-}
> >                     ^                    ^
> >if the estimated winning rate with true komi is less than .5.

Oups ! I forgot to divide by C... The equations here are not even
homogeneous ! It should read:

new_komi_ggmc = 
    truncation[(.5 - old_winning-rate) / C + old_komi_ggmc - lambda / (2
    C^2) ]^{+}

if .5 - old_winning_rate < 0, and

new_komi_ggmc =
    truncation[(.5 - old_winning-rate) / C + old_komi_ggmc + lambda / (2
    C^2) ]^{-}
            
if .5 - old_winning_rate > 0.

Don't forget C < 0, so the equations make sense.

Jonas