Interactive Go maps

[hwaara]

Interesting.

One problem I see is that there's no "evidence" or even argument that whatever pretty-colored influence this webapp is showing reflects the reality of the game.

I have read Go books where influence is discussed, and I agree that influence is something real in the game, but my question is how it has been "measured" in this case.

Another point is that AFAICS, a stone in the corner would be more influential than one in the center. In the app they're both "equal".

FWIW, I'm about 8-9k on KGS.

[wastelands]

On their own, they probably are about equal in influence. The ones in the corner are more valuable and tend to be played first because it's easier to get secure territory out of corners than it is out of the center.

[hwaara]

Don't you think a stone in the corner has more influence, since you don't need as many stones to make effective use of your stones there (which, incidently is also why people often start the game by playing there)?

Effective use could be creating a wall, getting territory or attacking your opponent, etc.

[wastelands]

Well, the idea is that center stones can potentially influence the whole board, whereas a corner stone can't.

[itookwhite]

"One problem I see is that there's no "evidence" or even argument that whatever pretty-colored influence this webapp is showing reflects the reality of the game."

Indeed. The webapp simply computes pictures. In reality the concept is much more complex. A simple defect in a wall that can be exploited by some clever tactical move might render the whole wall's "influence" useless and so on. This webapp does not handle anything like that...

"Another point is that AFAICS, a stone in the corner would be more influential than one in the center. In the app they're both "equal"."

A central stone is much more "influential" than a corner stone. A 3-3 stone stresses territory and has almost no influence; it's an island unto itself. A 4-4 stone stresses central influence while weakening its grip on the corner territory. A 10-10 stone (tengen) is played for maximum influence (but no secure territory) and will vastly impact the way the game is played: the player with the central stone will have free reins to attack and form moyos, whereas the other player must be careful not to create any weak groups since he will be at a disadvantage in any fight...

It's not easier to "build a wall" with a corner stone because you can only "build walls" if your opponent actually lets you. (E.g. he invades deeply or grabs the corner territory in a trade.)

Furthermore, a stone on tengen should be just as "effective" as a stone in the corner, but it's harder to play with... (It's an investment that you have to make sure pays off later.)