4463 enclosure 3-3 invasion

    Keywords: MiddleGame, Joseki

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This page seems to need a WME. Contents in BQM 180 can also be integrated into this page. --unkx80

Table of diagrams
Normal invasion becomes ko
This is also common.
Ignoring the ko
Ignoring the ko
Black tries to kill
Black tries to kill
Clamp to escape
Clamp to escape
Black blocks
Black blocks
Sacrifice one
Black key points
Placement
2-2 Placement
Placement
Placement
Another placement


(Moved from 4463 enclosure.)

[Diagram]

Normal invasion becomes ko

The 3-3 invasion here becomes ko in this main variation; though that's not the whole story.

See [ext] http://www.gobase.org/studying/articles/matthews/ko/part5/ for commentary. (without a gobase account, this link proved fatal to my firefox)

[Diagram]

This is also common.

unkx80: This is also common.



SiouxDenim: A line not covered in the above - how is White supposed to live if Black ignores the ko and plays this B8?

[Diagram]

Ignoring the ko

[Diagram]

Ignoring the ko

Charles Matthews I suppose White has a choice of W1 or a next. Black's play black+circle seems to reduce Black's possible loss in the ko; but it also must be a concession. In practice it would be hard to kill the corner now: White must have many local ko threats such as b. Black would quite like to exchange Black c for White d, to relieve shortage of liberties around the cutting point (circled point) - but this also helps White form eyes.


[Diagram]

Black tries to kill

This situation is not to be mistaken with 4-4 Point Low Approach Low Extension 3-3 Invasion, W5 here is not the normal move. Because B6 can try to kill the invasion stones.

[Diagram]

Black tries to kill

This is Black's most severe continuation. The fight will depend on the surrounding stones.



Locally, White is dead: after White b, Black c, d and e are miai. Note that B4 cannot be played at a.

[Diagram]

Clamp to escape



Rich: I can't see a good way for Black to stop White sneaking out with the clamp; couldn't this be better than the previous example, depending on surrounding stones?

Charles That's one from Get Strong at Crawl.

Rich: Sometimes better a crawling weasel than a dead lion, no? :) I see the point - if you have somewhere to crawl to, you're probably better off not invading at the 3-3 in the first place,

Charles Depends a bit; but the 4463 enclosure 2-4 approach might sometimes be more useful. Anyway, W5 of the initial diagram seems to be a pro move.

[Diagram]

Clamp to escape

Brian?: I don't see how the crawl is successful. B2 prevents it. A cut is unsuccessful and W3 at a makes B4 a successful defense against a cut.

Herman Hiddema: After W5, the marked black stones are in atari, and consequently the black position will collapse.


Anonymous: What about this?

[Diagram]

Black blocks

[Diagram]

Black blocks

unkx80: The result should be a ko. See tripod group with extra leg for a more detailed discussion.

MrTenuki: The problem I see with this variation is that White might see this as an improvement, since White, rather than Black, would take the ko first in this case. Assuming no outside support for either player, is it possible for Black to prevent this result?


[Joonas Tyystjärvi]: Supposing that the cutting point to the right of B2 is not usable, does this work? It seems to me that after W9, White is alive - are Black's moves correct? (Of course, the result is locally very bad for White.)

[Diagram]

Sacrifice one

[Diagram]

Black key points

-William 2d?

'a', 'b', and 'c' (followed by 'd' if white connects) are all more important than taking one stone. When seeking to kill, it is important not to try and separate your opponent's stones. It is better to squish them all together into an area too small to live.

White 5, incidentally, is not that strong. It gives up on the option to descend straight down, or play one to the left. Defending 1 with a hanging connection (for the ko) really is the best white can attempt for move 5. In fact, playing this sooner rather than later may be better -- 3 for 4 might be possible as a ko threat during the fight.


I think Black can kill by playing B6 at W7 instead. If Black omits B5, then White a Black b W5 makes life - Andreas

[Diagram]

Placement


kb: An interesting counter to the 3-3 showed up in one of my games.

[Diagram]

2-2 Placement


kb: In my game, I continued with W5, giving up the corner for the side (I had a little bit of strength on the left side to support these stones). My question, though, is what is the best way to continue locally in this situation (assuming Black has strength first in one direction, the other, both, and neither)? I didn't find any matches in Gobase.

[Diagram]

Placement


A variation

[Diagram]

Placement

How does B foil this? (I think B can try "a")


Another variation

[Diagram]

Another placement

What happens here?


Author(s):


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