Life In 19x19

Hi,

In the book "Making good shape", chapter one, the following example of good shape appear. Given the initial position:

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[go]$$Bc Black to play
$$ +---------------------------------------+
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ . . . . X O X X . . |
$$ . . . . . O O X . . |
$$ . . . . . . X O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

the sequence below gives White bad shape (called dumpling), while Black's center stones are projecting influence.

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[go]$$Bc Black to play
$$ +---------------------------------------+
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ . . . 4 X O X X . . |
$$ . . 7 3 2 O O X . . |
$$ . . . a 1 5 X O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

My question is: shouldn't Black worry right now about a cut at 'a'?

I think if B has already checked the ladder is good for B, then B doesn't have to worry about (a).
And if the ladder is a big problem for B, then B can connect at (a) instead of the extend on .

Note that W also has the option to atari the other stone:
( I didn't realize this is already covered in the book when I did this diagram. )

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[go]$$B :w6: connects
$$----------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ , . . . X O X X . . |
$$ . . . . 5 O O X . . |
$$ . . . . 1 2 B O X . |
$$ . . . . . 3 4 O X . |
$$ . . . . . 7 . O X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |[/go]

Perhaps one key point of this example is to show the tesuji of which
appears in other situations; for example, this joseki:

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[go]$$B
$$----------------------
$$ . . . . . . . . . . |
$$ . . . . . . X . O . |
$$ . . X X X . . X O . |
$$ , O O O O X X O . . |
$$ . . . . X O X O . . |
$$ . . . . . O O X O . |
$$ . . . . 1 . . X O . |
$$ . . . . . . . X . . |
$$ . . . . . . . . . . |[/go]

Yes, the point was the tesuji of , but there was no reference to the ladder.

I was thinking that even if the ladder doesn't work, maybe there is a tesuji for Black after a cut at 'a' - a loose lader or a net, but I wasn't able to find one.

nickxyzt wrote:In the book "Making good shape", chapter one, the following example of good shape appear.

In your copy of the book, is it under "Chapter One: The Efficiency of Stones,"
and under section "2. Dumplings" ? Maybe another key point is W's dumpling shape.

Sensei's page here leads to this review. I wonder if there exists another review, at pro level ?

From the book: "However, the two marked stones burden White's position with bad aji."

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

Then, the section proceeds to show the tesuji of .
So perhaps B would wait until the conditions are good for B to exploit this aji.

If the main point of the section is on dumplings, then maybe the initial tesuji is a secondary concern.
Perhaps how B replies to the cut depends on the whole board ?

Click Here To Show Diagram Code

[go]$$W
$$ ---------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ , . . O O O X X . . |
$$ . . X X O O O X . . |
$$ . . . 1 X X X O X . |
$$ . . 2 3 5 7 . O X . |
$$ . 8 . 4 6 . . O X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |[/go]

Another possibility, if the top is not important to B, and is a potential target ?

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[go]$$W
$$ ---------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ , . . O O O X X . . |
$$ . . X X O O O X . . |
$$ . 5 3 1 X X X O X . |
$$ . . 4 2 . . . O X . |
$$ . . . . 6 . . W X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |[/go]

Ok, thanks for the clarification.
The main theme is dumpling, so the stress is on .

It's clear for me now that Black should wait for a favorable context so that the cut is not a threat.
There is no net right now for the piece at 'a'.

EdLee wrote:From the book: "However, the two marked stones burden White's position with bad aji."

$$Bc
$$ ---------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ , . . . Y O X X . . |
$$ . . . . . O O X . . |
$$ . . . . . . Y O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code

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

Then, the section proceeds to show the tesuji of .
So perhaps B would wait until the conditions are good for B to exploit this aji.

I know there are always different views about forcing moves but I would like to play (at O14) immediately and when there is no clear way for Black to defend the remaining cut, I would play Tenuki.
In my opinion the situation could be compared with White playing at O14 himself. This should kill all Aji, shoudn't it?
But when Black already forced White into a dumbling shape and White decided to cut or play something larger in scale (either directly after Black plays Tenuki or later on) then Black might still have quite some Aji left.

@EdLee: Don't atari the cutting stone

If the ladder is bad, why not just:

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[go]$$W
$$ ---------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ , . . O O O X X . . |
$$ . . X X O O O X . . |
$$ . . . 1 X X X O X . |
$$ . . . . . . . O X . |
$$ . . . . 2 . . W X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |[/go]

Now white still has two problems. (Or maybe three, if we count )

Perhaps it would go something like:

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[go]$$W
$$ ---------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ , . . O O O X X . . |
$$ . a X X O O O X . . |
$$ . 5 . 1 X X X O X . |
$$ . . . 3 . . . O X . |
$$ . . . . 2 4 . W X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |[/go]

And the fighting is still unclear. Black can push out at a and white needs to be very careful, his top stones don't have that many liberties.

This looks playable for white only if he has support along the top side somewhere.

Maybe it's interesting to figure out how the sequence happened:

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

Locally, B has played 13 moves. W has played 12 (I'm guessing B captured 1 W stone at (b)).
It is still B's turn, so W tenuki'd once locally ?

HermanHiddema, thanks.

Click Here To Show Diagram Code

[go]$$Bc Black to play
$$ --------------------
$$ . . . . . X . . . . |
$$ . . . O X . X . . . |
$$ . . O O O X X . . . |
$$ . . . 4 X O X X . . |
$$ . . 7 3 2 O O X . . |
$$ . . . a 1 5 X O X . |
$$ . . . . . . . O X . |
$$ . . . . b . . O X . |
$$ . . . . . . . O . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

First, as Ed says, correct play depends upon the whole board.

Second, as Ed's diagrams illustrate, even if the ladder does not work, Black can sacrifice his stones in return for outside strength. This is called treating the stones lightly. Black can do that because they have already done their work. After all, in the initial diagram Black was outnumbered 2 to 11.

Third, takes gote in this diagram, which suggests two things. First, that the ladder works. Second, that Black is attacking the White stones on the top side. Black could take sente, after all, as part of treating the stones lightly. And if Black is worried about the cut, he could simply connect instead of extending with . He could also have made a play like "b", if he wished to attack the stones on the right, instead.

Fourth, forcing bad shape on White is good, even if Black later sacrifices his stones. Therefore, this kind of play is usually made early, without worrying about whether Black can save his stones.

EdLee wrote:Maybe it's interesting to figure out how the sequence happened:

$$B
$$ ---------------------
$$ . . . . . X . . . . |
$$ . . . O X b X . . . |
$$ . . O O O X X . . . |
$$ , . . . X O X X . . |
$$ . . . . . O O X . . |
$$ . . . . . . X O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code

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

Locally, B has played 13 moves. W has played 12 (I'm guessing B captured 1 W stone at (b)).
It is still B's turn, so W tenuki'd once locally ?

HermanHiddema, thanks.

Here is my guess for the last few plays.

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[go]$$W
$$ ---------------------
$$ . . . . . 2 . . . . |
$$ . . . 1 X O X . . . |
$$ . . 3 5 O X X . . . |
$$ , . . . 4 O X X . . |
$$ . . . . . O O X . . |
$$ . . . . . . X O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O X . |
$$ . . . . . . . O . . |
$$ , . . . . . , . . . |[/go]

is a mistake, OC.

The position looks contrived to me, but who knows?

As Black, I'd be happy to get the chance to fight over the ladder in the opposite corner as well. If white ends up extending, or playing a close by ladder breaker, I get a free move in the other corner. It's sort of like a picnic ko: black didn't have anything special going on in the area to begin with, so if he gets an advantage elsewhere it's a good trade.