4464 enclosure 3-3 invasion

  Difficulty: Advanced   Keywords: MiddleGame, Joseki, Question

Table of contents Table of diagrams
3-3 invasion
Joseki
Black tries to kill
Black fails
Another fail
Joseki II, part 1
Joseki II, part 2


Depending on the surroundings...
Push through and cut
Basic situation
Letting White connect
This may happen later -> no assured eye in the corner
Assured eye in the corner
Cutting
White lives too
What now ?

Invasion of the untouched enclosure

[Diagram]
3-3 invasion  


Joseki 1

[Diagram]
Joseki  

This is the standard joseki for the 3-3 invasion after a 4-4 6-4 corner enclosure. White is alive or will be able to escape at a.

[Diagram]
Black tries to kill  

If black resists with B1...

[Diagram]
Black fails  

After W1 - W9, Black can't block at B10 because White will play a and capture either of the marked stones.

Of course, going back to the original diagram, this means that if black adds another stone almost anywhere in this area, it forces white to respond with his corner group.

If he doesn't, Black's B1 will make the corner a ko for life. NormanP: How would it be a ko in that case? Wouldn't it just kill? Timm(5k): That's what it seems to me too.

[Diagram]
Another fail  

This B6 doesn't work either.


Joseki 2

Timm(5k)/Apr. 2014: This sequence needs confirmation.

[Diagram]
Joseki II, part 1  
[Diagram]
Joseki II, part 2  


Extend (mistake)

Timm(5k): Maybe this also needs confirmation ?

[Diagram]
 

This W2 is often seen at lower levels. If Black now answers at a, White will comfortably live at b, making a J+1 group.

[Diagram]
 

So Black should instead play B9 to kill white and be prepared to handle the cut at a.

[Diagram]
Depending on the surroundings...  

Dieter: Depending on the surroundings...

[Diagram]
Push through and cut  

Bill: Like this?

Timm(5k): I think White can still escape escape on the side though. But maybe it's still a good result for Black.


After a diagonal contact

[Diagram]
Basic situation  

In this situation, the 3-3 point is still available to White. There are three main responses for Black.

Letting white connect

Timm(5k): The sequence needs confirmation.

[Diagram]
Letting White connect  

Black can simply block at B2, letting white reduce the corner. After B4, White has no choice but to fall back at W5. (B4 at W5 is possible too.)

Bray(7k): Guo Juan (5p) includes B4 among her list of mistakes in this position. She covers this in "New Typical mistakes 10k - 1d lecture 3"

tapir: Has she B4 in particular listed as mistake or the sequence starting from B2? I was taught this to not play B4 at B5 anymore and/or defend a base in the corner once upon the time.

Bray(7k): After W1, black usually plays B2 or W3 (either is fine). The choice depends on the rest of the board. However, she explicitly lists B4 as an error in the sequence shown in this diagram. Reasons include: it's gote, it's small, and white get a strong shape. She likes the tesuji itself, but in this instance it's mainly a trick play (white falls to pieces if he tries to save the two inside stones).

[ext] http://internetgoschool.com/auth/lectures/1116.lecture The whole lecture is quite interesting. I don't have any stake in her site, other than being a member for many years.

tapir: No need to justify yourself for relying on Guo Juan (or any professional, really). I am, in fact, a former pupil myself. I agree.

There is one thing this sequence undeniably achieves: an assured eye in the corner. Guess this justifies the sequence in special cases. (Though can't watch the lecture - membership lapsed.)

[Diagram]
This may happen later -> no assured eye in the corner  
[Diagram]
Assured eye in the corner  


Cutting

[Diagram]
Cutting  

B2 aims at attacking the White stones on the outside, but lets him live in the corner.


Empty triangle

[Diagram]
White lives too  

The third one is the most complicated of all. White is able to live too with correct play and the White stones on the outside are not as weak as with the previous variation.


(Niklaus: Moved here from Changing Fuseki Dogmas.)


Much of this material appears at Joseki-related Life-and-Death example 5


Questions

[Diagram]
What now ?  

Timm(5k): This happened to me in a recent game. Can white still live in the corner if the peep has been played on the outside ?

Andeol?(2k): I can't be completely sure, but I feel like it probably can't.


4464 enclosure 3-3 invasion last edited by 176.143.112.23 on December 1, 2017 - 22:36
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