Fair enough, but I don't have a clue what that means. Would you care to explain.

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

What it means is that if the opponent gets 7 attacks moves in a row, he kills; i. e., if you answer the 6th attack move, you can live.

Anyway, that's the estimated number of attack moves. OC, if the opponent gets 6 free moves he can capture two of the four stones in the ponnuki shape.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

No, understand the 6 part. It is the highlighted part I need an explanation of.

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Bill gave a worked example of the PON algorithm in his first post on the subject: viewtopic.php?p=211105#p211105.

Btw I presume Tajima and Sanechika and names of 2 Japanese people. Who are they? I found this reference to the PON paper https://www.semanticscholar.org/paper/E ... 84c26cc397

Let us call an empty point that has a Manhattan distance of N from a group an Nth order dame of the group. The diamond shape has 9 first order dame (8 outside the eye, 1 inside), 12 second order dame, 16 third order dame, and 20 fourth order dame. The weights for the different orders of dame and the linear equation were empirically derived, but I am highly critical of the methodology and lay no store in the estimate. OTOH, I do think that the 4th order dame are in general relevant to the PON, so there is something there.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Tajima and Sanechika were at the Electrotechnical Laboratory in Tsukuba, Japan, in 1998, which was when their paper was presented, at the same conference where I presented my paper on evaluating superkos and multiple kos. I did not meet them, however.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Okay, that makes sense. Thanks. I did something similar 15 years ago when I did my counting lessons. But I used the ideas to do an estimate of potential territory that may be gains from the influence a group generates.

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Click Here To Show Diagram Code

[go]$$c
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . O . . X . . X . O . O O . . |
$$ | . . . O . . . . . , . . . . X X X . . |
$$ | . . . . . . . . . . . . X . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O X X X . . |
$$ | . . . . . . . . . . . . O . O X O . . |
$$ | . . . O . . . . . , . . . O O O O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O O . X . . X , . . . . . , X . . |
$$ | . . O X X . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

How do you estimate the territory for White's right side group? I estimate around 10 pts., which suggests that the group is not in any immediate danger and can ignore at least one attacking play; i. e., it has a PON of at least 2.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

The methods I described in those lessons would give it about 10-12 points, but it wasn' that clear cut. I used both probable and possible points, counting the possible for half weight.

_________________
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Inspired by Bill's example of a bulliable but isolated group from a Chitetsu-Dosaku game, I looked at the following very common and well known position from the Chinese fuseki, still being played.



The context of this game is a pro explaining that amateurs are prone to play A instead of White 1. White 1 looks small and leads to a bulliable group (though the bullying is not quite as aji-ful as the Dosaku game). In other words, Chitetsu's willingness to make that sort of group seems amply reflected in modern play, too. Personally, I have never liked this sort of White play, but it turns out that that was because I never really understood it.

Much to my surprise, when I looked at a significant proportion of actual games with this opening, in all but one case it turned out that this White group was a classic example of a Go Seigen group - indeed, the best I've ever seen. By that I mean that for a very long period of the subsequent game, all play in the SE quadrant of the board ceased. The tiny Go Seigen group had done a sterling job of dulling Black's prospects in this area. To borrow a chess term, it seems we can consider the GSG group 'thematic' in the Chinese fuseki.

I'm reminded of a classic example.

Click Here To Show Diagram Code

[go]$$Bc joseki
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . 3 . . 5 . . |
$$ | . . . , . . . . . , . . . . . 1 . 4 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Above is a joseki that pretty much everyone knows.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . 3 . . 5 . . |
$$ | . . . , . . . . . , . . . . . 1 . 4 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

So , above, is good for black. White's shape is cramped an inefficient. Later in the game, maybe it can be attacked.

But here....

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . 3 . . 5 . . |
$$ | . . . , . . . . . , . . . . . 1 . 4 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . B . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

The result is good for white. That's because, due to the marked black stone, this was already an advantaged area of the board for black. Therefore, black should expect an advantaged result.

From this I gather that a weak group or a group that can be attacked is ok in an area where the opponent already has an advantage. If you can minimize what your opponent gets in an area where your opponent is strong, that's ideal.

In the Chinese opening, black's marked stone gives a local advantage:

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . B . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . a . . . |
$$ | . . . O . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

So if white gets a weak-ish group in the 'a' area, maybe it's OK - if white sufficiently reduces Black's advantages area.

These days, it's not uncommon to see pros try variations as white in the Chinese opening, such as the following:

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . O . . O . . X . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . W . O . . . |
$$ | . . . O . . . . . X . . . X . , . . . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Since these more recent variations deviate from "standard", I suspect that pros these days are not 100% satisfied with the result of the classic way for white.

That being said, the old way still seems played sometimes, so perhaps there is variation in pro assessment.

Anyway, the biggest thing I get from all this is that the "good or bad" of weak attackable groups is relative. In the opponent's strong area, a living weak group may be just what you need. But if it's a situation that should have been advantageous to you and you come out with a weak group, you might have problems

_________________
be immersed

No, it's not clear cut. I didn't mean to give the impression that it was. My methods also yield about 10-12 points, but I discount their results in the center.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

This variation was proposed in one of the go magazines that I read back when the Chinese opening was starting to become popular.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Reminds me of the field of mathematics. A lot of really fascinating tricks and proofs are thousands of years old.

Or "Deep Learning", which is so popular these days. Many of the techniques are decades old, but are only now being used for powerful applications.

I guess with deep learning, computer hardware advancements have played a role in what can be achieved. What's trendy plays a role, too, I guess.

A lot of copycats in all fields, then someone starts having success with something "new", and that sets an example for more imitation :-p

_________________
be immersed

The final game of the Meijin title match currently in progress between Iyama and Takao had a shape which rather reminded me of John's "looks thick but is really thin" wall with a net example. Now it wasn't as bad as that as it has some eyespace towards the edge as well as the netted stones, rather than being plastered against a strong corner, but still I feel the result was not so great for black (Iyama) as white lived in the corner, got a ponnuki to develop top left, got the peeps and sente. This shape arose from an ignored peep (inside 4-4 approach kick extend one-space jump) for losing the ko at the top. White continued with the peeps immediately then reducing the bottom with a-j

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X X O . . . . . . . . . . . . . |
$$ | . O O X O . O . . . . . . . X . . . . |
$$ | . . X O . O X . X , . . . . . , X X . |
$$ | . . . O O . . O i . . . . . X X O . . |
$$ | . . . . . . . . . . . . . . X O O . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . . . X O h . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O , . . . . . , . . . . . O . . . |
$$ | . O . O . . . . . . . . . . . . . . . |
$$ | . . O X c . . . . . . . . . . . . . . |
$$ | . . X X d X . . . . . . . . . O . . . |
$$ | . . X O O b a . . . . . . . . . O . . |
$$ | . O X X O f e . . . j . g . . O X . . |
$$ | . X O O X X . . . , . . . . O , X . . |
$$ | . O O X . X . . . . . . . X X X . . . |
$$ | . . O . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]