[computer-go] f(score) instead of sign(score)

[Sylvain Gelly]

> So MoGo may be
>  using a floating point function to estimate the score of a playout,
>  otherwise there would be no reason to use floating point. But I may be
>  guessing wrong. Maybe they can tell us ?

We don't (at least up to the release, I don't know everything they are
doing now). Using the floats was for flexibility, because we did try
transformation as suggested and we also tried decays. We wrote things
before knowing what will work so the choices were always "does it
allow us to experiment ideas?".

Cheers,
Sylvain