BQM 342

    Keywords: Question
[Diagram]
Joseki  

Imagist: This is a common joseki resulting from a 3-3 invasion under a hoshi stone. In the common variations for W8 at a and b, black can forcibly retake the corner while giving white a ponnuki along one of the sides in exchange.

My question is: what if white cannot benefit from a ponnuki, and instead wishes to keep the corner? What is the best way to do this?

xela: If black is so strong on the outside, then maybe W2 is not the best invasion, and white might consider playing at B3 or at d instead? It's hard to say without seeing a full-board position.

[Diagram]
Best?  

Imagist: This is the best continuation I could come up with. This seems very good for black. The only thing I see going for white in this situation is sente.

[Diagram]
Better?  

xela: If white is determined to keep the corner, I think W1 is still a good idea, because white will have the chance to play a ladder-breaker later (or maybe a).

Imagist: I see, an example of play kikashi before living.

[Diagram]
Variation: why black must protect  
[Diagram]
Variation: white is too submissive  

[Diagram]
Hane and connect  

Bill: W1 - W3 is usual to retain the corner. W5 can also be at a. (If B2 at a, W3 at B4.)

[Diagram]
Black gets greedy  

Bill: If B1 - B5, after W6 something has to give.

Imagist: What gives after B7? (Or B7 at a). Am I missing something? (A way to capture B3?)

[Diagram]
corner  

Imagist: Nevermind, I got it. I wish I could read.

Herman Hiddema: Alternatively, you could play 5 directly if you want to keep more aji in the marked stone (if black plays at W1 to force a, white has the option of later playing at B4 )

[Diagram]
Also might work (with ladder) a/b miai.  

Imagist: This seems like it could be better in some situations. If black a, after white b, W1 maybe has aji?

Bill: If this ladder works or W1 has aji, I am not sure why the ponnuki isn't OK.

Imagist: Point taken.



[Diagram]
Problem?  

Bill: If the ponnuki is not good for White, there is a possible problem with W1. Black may be able to play B2. In this variation, if black+circle and B4 are safe, things are difficult for White. And even if Black plays B6 somewhere else, White cannot make two eyes in the corner.

Alex: This is an example of the general principle that it's impossible to live at 3-3 (or just about anywhere else) if escape into the centre is not a valid threat (because the area is completely surrounded by the opponent's thick stones). It always surprises me how many SDKs and even amateur low dans aren't aware of that.

However, if that's the case, Black has other ways of preventing two eyes that will usually be better than this double-hane anyway.





BQM 342 last edited by Dieter on July 5, 2008 - 12:49
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