Re: computer-go: Evaluating positions

["Vlad Dumitrescu" <vladdu@xxxxxxxxxxx>]

> Sorry, I do not understand where this number comes from, and what does it
> mean?

Well, I said from the beginning, this is not meant to be a computable description, but more of a conceptual description. The numeric values were meant just as an example.

> > The strength is also measured from 0.0 to 1.0, where 1.0 is
> > unconditionally alive (even if passing all the way).
 
> Again, could you elaborate? What is the value for a group that can stay
> alive if every attacking move can be answered by a suitable defence? (that
> is, in ordinary go terms, "unconditionally alive"). 

I don't pretend that value can be computed easily. If it did, we wouldn't have to read life-and-death problems :-) 

If such a value exists, I think it is not a regular number as we grew to know and love, but maybe something more alike the values used by Elwyn Berlekamp for endgame analysis.

> What does value 0 mean (no group at all?).
No, it means "dead even if the opponent is passing all the time".

> Some critical questions and comments:
>   - You talk of a strength of a group. How do you define a group?
In this case, just a bunch of stones.

>   - I have a strong feeling that the essence of go can not be captured
>     in one number, not even one number for each point on the board.
Of course it isn't really possible to capture the essence of the game in just a number table (short of actually exploring the whole game tree). But on the conceptual level, it is the balance between influence and strength that governs the game.

> Even if I remain sceptical, I wish you best of luck. Keep us informed on the
> progress.
I doubt this has any practical meaning. Not in this crude form. But what I'd really would like to see is a mathematical model of the game (in a similar way to Berlekamp's). I am probably not suited to develop that theory, but one can only try! :-)

/Vlad