Re: [gnugo-devel] invasion question

[nando]

On 12/1/06, alain Baeckeroot <address@hidden> wrote:
> Hi
>
> It seems that GNU Go very often miss "classical" invasions
> below 4 th line too streched B stones (like in H9 game)
>
> A quick test seems to show that there is no pattern for such invasion
> (...)

Unfortunately, GNU Go isn't fantastically strong at life & death, not
to mention sabaki. So it's probably on purpose that such patterns are
missing.

> (...) And i saw a rather big malus for invasion moves (near 10 points)

Correct. See strategic_penalty() in value_moves.c

> Is it done on purpose ? (to prevent hasty invasion which fireback)

Exactly.

> Is it worth digging, and adding test cases (i found less than 10 invade test)

Possibly. IMHO a serious approach of this issue would have to start
with the creation of a new primitive, something like owl_invasion (and
possibly owl_threaten_invasion). That would allow to more solidly test
pattern-generated potential invasion moves. Then we could use the
result to value the moves more properly (the penalty should still
apply I think). But I doubt a bit that the engine is up to such a task
for the moment.


Loosely related: GNU Go also almost totally lacks reduction moves generators.

-- nando