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How to handle an invasion in a 4x4 joseki
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Author:  zizicu [ Thu Nov 15, 2018 2:27 pm ]
Post subject:  How to handle an invasion in a 4x4 joseki

Hi,

what is the best way to handle the following invasion ?
Let's say I want to keep as much territory in the corner as I can.
If there are resources on the web, please post them here.
Thank you.


Author:  Calvin Clark [ Thu Nov 15, 2018 2:57 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

Please post more of the board, ideally a whole-board position. It matters a lot whether there is a white stone at H17, for example. Without help, the attachment at N16 would be a more common invasion point for white, so I am wondering how it would be that you find yourself getting into this position often enough to ask.

For example, if the board is like this and white just invades with :wc:, you can try a leaning attack. Even if white lives, the fight is acceptable for black. Although, truth be told, black can also tenuki in this position since white has invaded in a small area.

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . X . W . . . . X . . |
$$ | . . . X . . . . . , 5 6 9 X . X . O . |
$$ | . . . . . . . . . . . 7 8 . . . 4 . . |
$$ | . . . . . . . . . . . . . . . 3 O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 1 2 . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Author:  zizicu [ Thu Nov 15, 2018 3:04 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

Hi,

I am not having a specific game in mind.
The asumption is there are no stones close, let's say there are stones in the other 3 corners, white and black.
I do not want specific variations, more like how to approach this situation.

Author:  Uberdude [ Thu Nov 15, 2018 3:31 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

zizicu wrote:
I do not want specific variations, more like how to approach this situation.

Keep your stones connected. Build a wall. White may make a miserable small life or die.

Author:  Calvin Clark [ Thu Nov 15, 2018 3:50 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

The reason it's hard to find games that match this position is because pros like sente and often don't finish the black joseki at the top. So you see stuff like this from a game between Cho Chikun and Otake Hideo:

Click Here To Show Diagram Code
[go]$$B Moves 31 to 33
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O X . . . . . . . X . O . . . |
$$ | . . O , X X . . . , X . . . . , O O . |
$$ | . . . . . . . . . . . . . . . X X O . |
$$ | . . O . . . . . . . . . . . . . . X . |
$$ | . . . . . O . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 2 , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . 1 . 3 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . O O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . O . . . . . , . . . X . X . . . |
$$ | . . O . . X . . X . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This is why I say you might consider tenuki. If you hadn't told me white had just invaded in your position, I would have thought it's white to move. :)

I am going to change the board a bit from my original position. Another locally common move is the top attachment at :b1:. Because white has a helper stone on the top, white can try to connect to :w6:, but this sente for black. Now black has to figure out how to use those outside stones, which is not so easy because of the stable white group on the right. I think LZ would still play as above or directly at :b3: instead of :b1: here and just fight like mad, but this is a simpler strategy. If black can get a stone near 'a' there are follow-ups against white. I think it's a game still.

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . 6 4 . . . . . . . . . |
$$ | . . . . . . . O . X 2 O . . . . X . . |
$$ | . . . O . . . . . 5 3 1 . X . X . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . a . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . 7 . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Author:  Kirby [ Thu Nov 15, 2018 5:14 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

If you want a general principle, M16 is your answer.

But if its a game, there is no choice but to read variations and pick the one you like best.

Making wall with M16 will always be decent. Read our each situation to see if you can get better.

Author:  ez4u [ Thu Nov 15, 2018 7:12 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

zizicu wrote:
Hi,

what is the best way to handle the following invasion ?
Let's say I want to keep as much territory in the corner as I can.
...

zizicu wrote:
I am not having a specific game in mind.
The asumption is there are no stones close, let's say there are stones in the other 3 corners, white and black.
I do not want specific variations, more like how to approach this situation.

The problem is that your goals are inconsistent with your previous play. If you want to keep as much as possible in the corner, you should only extend to L17. The 3-space extension to K17 leaves the standard invasion point at M17 or the attachment at N16 behind. Going back further, if you want to keep territory in the corner, play 3-4 rather than 4-4!

However, if there are still only a few stones on the rest of the board, you should not be looking to settle for as much as possible in the corner when White invades. There must be larger areas on the board. If the only other thing on the top of the board in the OP is a Black stone on the upper left 4-4 point, the area to the left of K17 is more open and worth more than the narrow space that White has invaded. When White invades too early the question is how best to exploit the error in timing, not how to keep another point or two in the corner.

You can learn "standard" responses for the local situation, but they will tend to blind you to the larger considerations.

Author:  Bill Spight [ Thu Nov 15, 2018 11:57 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

zizicu wrote:
Hi,

what is the best way to handle the following invasion ?
Let's say I want to keep as much territory in the corner as I can.


Let's not. As others have indicated.

Quote:

If there are resources on the web, please post them here.


Not easy to find. As Calvin points out, pros do not play this way.

ez4u wrote:
The problem is that your goals are inconsistent with your previous play. If you want to keep as much as possible in the corner, you should only extend to L17. . . .

However, if there are still only a few stones on the rest of the board, you should not be looking to settle for as much as possible in the corner when White invades. There must be larger areas on the board


Worth repeating. :D

However, even if there are larger plays on the board, :wc: is probably a mistake. Punishing it has a psychological value. Even better, if White makes small life with gote, he might not even realize he has been punished. ;)

Click Here To Show Diagram Code
[go]$$Bc Save the corner!
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . X . W . 1 . . X . . |
$$ | . . . , . . . . . , . . . X . X . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


:b1: saves the corner and threatens to capture :wc:. I hope it is obvious that :b1: sucks. ;)

Click Here To Show Diagram Code
[go]$$Bc Standard attacks
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . d . X . W . . . . B . . |
$$ | . . . , . . . . . , a b . X . X . O . |
$$ | . . . . . . . . . . . c . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


"a", "b", and "c" are standard attacks against :wc:. "c" the least common. The general idea is to threaten :wc: and make strength as White defends it. :wc: is usually a mistake, unless White has a stone at "d" or something. The :bc: stone is important for two reasons. It strengthens the Black corner, and it makes it impossible for White to make much territory with :bc:, if White can live at all.

Click Here To Show Diagram Code
[go]$$Wc Reduction
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . X . . . . . . X . . |
$$ | . . . , . . . . . , . . 1 X . X . O . |
$$ | . . . . . . . . . . . . 2 . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


One usual play against the Black position is the attachment at :w1:, a reducing play. Often Black attacks with :b2:.

Click Here To Show Diagram Code
[go]$$Bc Small life, maybe
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . X . W . 3 2 . B . . |
$$ | . . . , . . . . . , 1 . . X . X . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


:b1: is a strong attack, making it impossible for :wc: to escape and difficult for White to sacrifice it. White would like to play the peep at :w2:, but :bc: makes :b3: a nice play. White will have to find something else.

Play around with this position. Maybe White can make small life, maybe a ko, maybe not. ;)

Author:  Gomoto [ Fri Nov 16, 2018 10:27 am ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . O . O . O X . . X . . . . O . . . |
$$ | . . X O O O X . . X O O . O . . X . . |
$$ | . . X O X X . X . , X O . . . X . . . |
$$ | . O O X O X . . . . . O . . . . . . . |
$$ | . O X X . . . . . . . . . . . X . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . W . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . X . . X . . |
$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . . , . . . . X , . . . . . , X O . |
$$ | . . . O . X . . . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . O . O . O X . . X . . . . O . . . |
$$ | . . X O O O X . . X O O . O 8 . X . . |
$$ | . . X O X X . X . , X O . 7 . X . . . |
$$ | . O O X O X . . . . . O . . . 9 6 . . |
$$ | . O X X . . . . . . . . . . . X . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . 3 2 O . . |
$$ | . . . O . . . . . . . . . . . 1 . . . |
$$ | . . . , . . . . . , . . . . . , X 4 . |
$$ | . . . . . . . . . . . . . . . . . 5 . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . X . . X . . |
$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . . , . . . . X , . . . . . , X O . |
$$ | . . . O . X . . . . . . . . X . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]




Huang Chen 5p - Jiang Weijie 5p, B+Resign (Komi 7.5)
13th Chinese League A, round 4, 2011-05-21

Author:  zizicu [ Fri Nov 16, 2018 1:50 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

Thank you all for the answers.
A lot to learn from them.

Author:  lightvector [ Sun Nov 18, 2018 5:03 pm ]
Post subject:  Re: How to handle an invasion in a 4x4 joseki

By the way, if you every do want some more specific variations for that position, I've found InternetGoSchool to have some resources on it, for example: https://internetgoschool.com/lesson.vhtml?ls_id=303

These are of course only a starting point (in a real game you still have to judge what to do), and in the age of strong bots changing some pro thinking about certain joseki various early-game trades, some of the material on the site is outdated, but I personally found some of these lectures and problem sets very useful to learn and drill.

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