Re: computer-go: Evaluating positions

["Vlad Dumitrescu" <vladdu@xxxxxxxxxxx>]

From: "Heikki Levanto" <heikki@xxxxxxxxxxxxxxxxx>
> On Sun, Jun 17, 2001 at 09:33:49PM +0200, Vlad Dumitrescu wrote:
> > In the end, the list came down to two items, that are independent as far
> > as I can tell (for statical evaluation):
> >     - influence (of a group)
> >     - strength (of a group); this includes life/death
> 
> I am not sure I buy this. For the first, I believe those two are related.
> A strong group radiates more influence than a group that have many
> weaknesses, because the opponent can get to threaten those weaknesses, and
> thus play many stones to neutralize the influence, in sente.

I think there is a different meaning of the word "influence" that we are using. Otherwise I agree with you completely! :-)

Let me explain my way of seeing things.

I call influence of a group of stones a quality unaffected by the strength of that group. Stones of opposite color may be removed from the board when estimating it. Each empty point has a value between 0.0 and 1.0.

The strength is also measured from 0.0 to 1.0, where 1.0 is unconditionally alive (even if passing all the way).

The other influence we can call "compound influence" and can be in the simplest form computed by multiplicating the values above.
 
> When the game is over, it all comes down to a balance of territory. 

Of course. Territory is the areas where a player has influence at the end of the game, when all groups are either dead or alive, and there are no dame.

As I see it, the purpose of the game is to obtiain as much influence as possible, while keeping an enough amount of strength to assure life at the end of the game. Of course, at the same time one has to try to prevent the other player to do the same for himself.

Does that seem too strange?

regards, Vlad