Re: [gnugo-devel] trevor_1_15.2

[Arend Bayer]

> Trevor wrote:
> > http://www.public32.com/games/go/trevor_1_15.2
> >  - removed  "strategic effect".
> > 
> > The strategic effect seems to cause almost as many problems as it solves.  
> > Here's a list of FAILURES (35) / PASSES (26) with removing the effect.
> > There are a lot of fixmes in this section of code.  Is this effect 
> > really necessary?  If so, it probably needs an overhaul.
Wow that would be a major change! I don't think there is much to add
to Gunnar's reply; I believe the "strategic effect" produces useful moves
more often than not. OTOH the PASSes of Trevor's patch could show us where
we need to improve the current implementation. 

I will probably try to play around with this (but won't have time until
two weeks from now). The first thing that comes to my mind is that I do
not like the direct proportionality of the strategic effect to the
effective dragon size. Direct proportionality seems to assume that
attacking a group increases the probability to capture it. In reality,
you cannot capture it, buy you benefit from keeping your opponent busy
defending, while you are taking useful territory/influence with the
attacking moves. This effect is about the same for all group sizes, unless
the group is so small that the opponent can easily sacrifice it. So maybe
upper bounds for the strategic effects would make sense? I'd imagine
s.th. like 10 pts for a weak genus 1 group with some space to run. Also,
I guess that the strategic effect for alive (but not strongly alive)
groups is overvalued, but here I might be wrong.

Arend