Re: [gnugo-devel] joseki database

[Heikki Levanto]

On Mon, Dec 02, 2002 at 10:57:06PM +0200, Paul Pogonyshev wrote:
> i'll take it. besides, tree-based matching will be a step towards a joseki 
> reader (a one that chooses a joseki move by evaluating all possible joseki 
> outcomes in terms of moyo/influence).

If you haven't fixed your sigths to some solution already, I have a few
points I'd like to mention for possible discussion.

* Although choosing from "all possible" joseki outcomes sounds like the
proper thing, it may be too expensive (thousand variations of the taisha).
But often a move has a meaning, a direction it is pushing the game. It might
be useful to express this as a likely outcome position, and choose according
to that. Maybe (later?) a selection of a few possible outcomes. The whole
decision tree (who decides what and where) can be overly complex.

* Not sure what sort of "tree-based" matching you are going to do, but if it
based on following the game, watch out for situations where a player
deviates from the joseki, and later the game reaches a well-known position.
If white starts at 6-3, and black approaches 4-4, and white tenukis, we
have a classical 4-4 joseki position... This may not happen all too often in
the games of the Great Masters, but when humans play against a "mere
computer", this is the kind of tricks they hope for the program to fall
into. And we hope not to...

* Choosing the best-looking joseki is no use, if we can not handle the
resulting position.  No point in aiming for a slightly better fighting
position if we know our fighting ability is weak - or staying away from a
slightly bad fighting joseki if fighting is our best side... Tuning this by
hand will be tedious, and needs to be redone when even the balance of the
engine changes. Doing it automatically (learning) has a great number of
problems as well.. In short - choosing the right joseki is not easy :-)

* A joseki is not only the well-known sequence of plays, but also the reason
behind every one of them. If the opponent blunders in the joseki, we ought
to know what to do about that. As Kageyama said in "Lessons in the
Fundamentals of Go": Joseki are not to be momrized, but to be discovered.

I know that I am setting up some hard requirements here, and I will not
complain if you fail every single one of them. I just want to mention some
thoughts that might be useful to discuss before coding a lot... But, if you
have an idea you want to try out, go ahead - I will be thelast to complain
if we get something better than before...

Best of luck

   Heikki



-- 
Heikki Levanto  LSD - Levanto Software Development   <address@hidden>