RE: computer-go: Scoring

["T.R. Christie" <trc23@xxxxxxxxxxxxxxxx>]

Im interested to know, has anybody else
written static scoring algorithms?
I think a static scoring algorithm that gives good results
would be very desirable, becuase as soon as you start
using searching the complexity of the problem can become huge.

> I would like to undestand your method better because it looks very
> interesting - similar or better than mine. Please see questions below.
I think the two could fairly easily be combined.
The first pass would be the benson absolute life/death,
and would set the status of some of the score areas.
The remaining contested score areas (stuff that did not
meet the rigerous requirements of bensons') could then
be scored using my algorithm.

I think final result would be a static scoring algorithm
that would give better results than either of our two algorithms.


>> a black score area is a string of [white OR empty] intersections
> Do you mean a _maximum_ set of connected white or empty intersections?
yes.

>> two score areas can be said to intersect iff:
> Do you mean two scoring areas of different color (one black, one white)?
two score areas of the same color cannot intersect,
or they would be the same score area.
So, yes.

>> 1. the status of all score areas is initially CONTESTED
>>
>> 2. any score area that intersects with one and only one
>>      opposing score area has it's status set to SCORING
>>
>> 3. any score area that intersects with a SCORING score area
>>      has its status set to NON-SCORING
>
>If A intersects B, then B intersects A, therefore SCORING score areas
>would also need to be set to NON-SCORING ?

No.  This is because score areas have the property
that if a score area is contained (intesects with only one
other score area)  It will never intersect with another
contained score area.

There is only one exception to this which must be dealt with specially:
* :  If there is only one score area of each colour on the
   board (eg around the start of the game), each will be contained
   by the other.  In case both score areas should be left CONTESTED


> > a fix, to cope with seki:
> >
> > any score area consisting of exactly 2 empty intersections,
> > and at least one coloured intersection is always CONTESTED,
> > and may not be changed by steps 2, 3 or 4.
>
> Too simple. Sekis can have 1 liberty in common, or 2 or 3, or even more!
> This includes the "final" state of a seki, where neither player can add a
> stone.
Id didnt really think this one through properly.
What is an example of a 3(or more) liberty
seki that is in the final state?
Ill have to find another way around this...


    tom