Life In 19x19

Uberdude wrote:you would find this has a bigger number.

$$Wc Clear influence
$$ -------------------------
$$ | . . . . . . . . . . . .
$$ | . . O O X . . . . . . .
$$ | . . O X . X . . . . . .
$$ | . . O X . . . . . , . .
$$ | . O X . . . . . . . . .
$$ | . O X . . . . . . . . .
$$ | . . X . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$

Click Here To Show Diagram Code

[go]$$Wc Clear influence
$$ -------------------------
$$ | . . . . . . . . . . . .
$$ | . . O O X . . . . . . .
$$ | . . O X . X . . . . . .
$$ | . . O X . . . . . , . .
$$ | . O X . . . . . . . . .
$$ | . O X . . . . . . . . .
$$ | . . X . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$[/go]

Influence stone difference = 7.

cyclops wrote:under Robert influence is a compound object consisting of several numbers ( 5 if I remember correctly ). One position compared to another might be superior in some numbers but inferior in other. His influence does not provide a total ordening. This significantly complicates the application of this concept.

It is the reality that influence is not basic and simple. The definition identifies the minimally necessary information if one wants to get a reasonably complete information. E.g., knowing that a moyo is surrounded by only stones of its player is insufficient information. One must also know whether and how well the opponent can invade and live or connect (by running out).

Although reality and so the definition is complicated, application can be made as easy as possible for a purpose of application! In particular, one can consider only 1 or 2 of the 5 (or 6) parameters, if already they provide sufficient information for the purpose of application.

Remember that, although 5 numbers can be involved, their interesting values tend to be restricted to -2 (or smaller), -1, 0, 1, 2 (or greater), *. (Usually, the territory-parameter needs only the values 0 or 1.)

5 values sounds like a lot, but what do they describe?
- How well does Black live?
- How well can Black connect?
- How well does White live?
- How well can White connect?
- Does the player, who obviously is the one with territory potential on an intersection, already have territory there or does he need to make (only) another play to get territory there?

These are questions one should be asking oneself and answering anyway. So why not answer the questions accurately by determining the numbers, when this accuracy is useful for a particular purpose of application?

If one neglects to reflect these questions, then one makes too rough judgements such as "Black has a moyo here. I do not care if a reinforcement is neeeded. If White invades, I pray and try to kill." - Good strategy comes from (more) accurate judgement.

It is sometimes sufficient to apply only the other definition, that of influence stone difference. It relies on only 1 number.

RobertJasiek wrote:

Uberdude wrote:you would find this has a bigger number.

$$Wc Clear influence
$$ -------------------------
$$ | . . . . . . . . . . . .
$$ | . . O O X . . . . . . .
$$ | . . O X . X . . . . . .
$$ | . . O X . . . . . , . .
$$ | . O X . . . . . . . . .
$$ | . O X . . . . . . . . .
$$ | . . X . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$

Click Here To Show Diagram Code

[go]$$Wc Clear influence
$$ -------------------------
$$ | . . . . . . . . . . . .
$$ | . . O O X . . . . . . .
$$ | . . O X . X . . . . . .
$$ | . . O X . . . . . , . .
$$ | . O X . . . . . . . . .
$$ | . O X . . . . . . . . .
$$ | . . X . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$[/go]

Influence stone difference = 7.

And same for this? This influence is not so good as less eyeshape and doesn't reach as far to the right. Would it differ in another of your metrics?

Click Here To Show Diagram Code

[go]$$Wc Not quite so good influence
$$ -------------------------
$$ | . . . . . . . . . . . .
$$ | . . O O X . . . . . . .
$$ | . . O X X . . . . . . .
$$ | . . O X . . . . . , . .
$$ | . O X . . . . . . . . .
$$ | . O X . . . . . . . . .
$$ | . . X . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$[/go]

Uberdude wrote:And same for this? This influence is not so good as less eyeshape and doesn't reach as far to the right.

If you want to measure how far influence reaches (rightwards) and how alive the thickness is etc., then the 3-parameter thickness definition and the 5-parameter influence definition (applied to empty intersections right of the wall) are possible tools while the influence stone difference does not assess it at all.

For influence stone difference, your position has the value 6 because one black stone does not contribute significant influence (removing the stone has an only marginal effect). Those that do are marked here:

Click Here To Show Diagram Code

[go]$$Wc Stones creating significant influence
$$ -------------------------
$$ | . . . . . . . . . . . .
$$ | . . O O B . . . . . . .
$$ | . . O X B . . . . . . .
$$ | . . O B . . . . . , . .
$$ | . O B . . . . . . . . .
$$ | . O B . . . . . . . . .
$$ | . . B . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$[/go]

Would it differ in another of your metrics?

In all of them, although part of the parameters might still be the same.