3-3 invasion question

Uberdude · Post by **Uberdude** » Tue Jul 23, 2019 2:18 pm

Hades12 wrote:I like this variation. Black can't cut C5 due to a liberty shortage right?

Are you worried about white squeezing? White can't keep it together when black cuts at 7 (and can't win ko):

Click Here To Show Diagram Code: [go]$$c Bad for white $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . . . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . O 1 O . . . . . . . . . . . . . . . | $$ | . 4 X O . . . . . , . . . . . X . . . | $$ | . 2 X O 7 . . . . . . . . . . . . . . | $$ | 6 X 5 X O . . . . . . . . . . . . . . | $$ | . . 3 . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White is just happy to capture and black made white stronger (weak wall becomes thick with ponnuki) is too costly for being able to connect and block at b2. Black could try a=d first as a trying to make c6 heavy and maybe get sente plan but it's not clear they are good exchanges

Click Here To Show Diagram Code: [go]$$c Bad for black $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . c . . . . . . . . . . . . . . . . | $$ | . X b d . . . . . . . . . . . . . . . | $$ | . X O a . . . . . . . . . . . . . . . | $$ | . O 1 O . . . . . . . . . . . . . . . | $$ | . 3 X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O . O . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Hades12 wrote:So he takes, and then white protects the cut at "a", or plays the outside at 2.

$$c This is not a label for the diagram.
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Click Here To Show Diagram Code
[go]$$c This is not a label for the diagram. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . . . . . . . . . . . . . . . . | $$ | . X . . . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . O a O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X . X O . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

2 isn't good here, black cuts, and pushes in sente to stop white turn in sente for a good result. Black got a chunky territory in sente in white's corner and the wall has weaknesses at a/b to exploit in the future

Click Here To Show Diagram Code: [go]$$c $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 6 . . . . . . . . . . . . . . . . | $$ | . 5 2 . . . . . . . . . . . . . . . . | $$ | . X 4 . . . . . . . . . . . . . . . . | $$ | . X O . a . . . . . . . . . . . . . . | $$ | . O 3 O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . b . . . . . . . . . . . . . | $$ | . X . X O . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

So white should connect, and it's like the direct connection except black can't choose to e2 extend, but only has the choice to play from the 2 stones if he wants to continue locally, e.g. extend at 3, if white plays checking extension black defends and is putting some pressure on the white wall whilst settling as f3 peep is incoming.

Click Here To Show Diagram Code: [go]$$c $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 4 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 3 , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 5 . . . . . . . . . . . . . . . | $$ | . X . . . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . O 2 O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . a . . . . . . . . . . . . . | $$ | . X . X O . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

and if white presses black just makes a 2-space extension and might save the 2 stones later which concerns base of both.

Click Here To Show Diagram Code: [go]$$c $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 5 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 3 , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . a 4 . . . . . . . . . . . . . . . . | $$ | . X . . . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . O 2 O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X . X O . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Uberdude · Post by **Uberdude** » Tue Jul 23, 2019 7:51 pm

Also c1 descent isn't really aji keshi, as aji keshi refers to an exchange which is one of severable plausible choices that after a possible future sequence of play might be good or might be bad and because you can't predict the future is better left unplayed; but the c1 b2 exchange is just always bad. It's mochikomi, loss without compensation as there's no realistic way of it being a good exchange. About the only positive thing I can find about it is the distant possibility that if black plays f4 and white peeps at g2 and black ignores then if white pushes and cuts then f2 becomes a sente not gote cut.

Hades12 · Post by **Hades12** » Wed Jul 31, 2019 12:16 pm

Uberdude wrote:Also c1 descent isn't really aji keshi, as aji keshi refers to an exchange which is one of severable plausible choices that after a possible future sequence of play might be good or might be bad and because you can't predict the future is better left unplayed; but the c1 b2 exchange is just always bad. It's mochikomi, loss without compensation as there's no realistic way of it being a good exchange. About the only positive thing I can find about it is the distant possibility that if black plays f4 and white peeps at g2 and black ignores then if white pushes and cuts then f2 becomes a sente not gote cut.

Ran the joseki through OGS AI (which I think is Leela) and it says that the descent there loses 19 percent win rate. After black connects at B3 he has a win percentage of 75.4%. AI really does not like the descent. IF I play C8 outright it says it is okay still, only a 3.9 percent change. I wonder why the descent loses almost 20 percent chance of winning for white.

And the AI says instead of continuing after Black plays move B7 to tenuki and play the 3-3 point in the LR.

clemi · Post by **clemi** » Wed Nov 13, 2019 5:02 am

Just saw an almost similar shape in Yeonwoo's youtube channel. Maybe, her explanation could be of some help...

https://youtu.be/1qpSyOpK-xw?t=369

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3-3 invasion question

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