another joseki question

dangerdoom · Post by **dangerdoom** » Tue Sep 01, 2015 10:20 am

I played a game in which i pincered in the middle of a black formation and my pincer was surrounded on a bigger scale than I would have liked. I tried to pull the pincer stone (move 2) out with pretty bad results.

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

The continuation from the game is below. But my question is, if White doesn't pull the stone out, is the result okay? How can White proceed in the game from here? Any thoughts of how to use the aji of the surrounded pincer stone? And secondly, is there an effective way to pull out the pincer stone?

Click Here To Show Diagram Code: [go]$$Wcm8 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . O . . . X . . O 9 X 6 . O . . | $$ | . . O , . . . . . , X 8 1 3 4 O . . . | $$ | . . . . . . . . . . . 7 2 X 5 . . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . X . O . . . , . . . . . , . . . | $$ | . . . . X O . . . O . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$cm14 $$ --------------------------------------- $$ | . . . . . . . . . . . . . 7 . . . . . | $$ | . . . . . . . . . . . . 4 2 3 X 6 . . | $$ | . . . . O . . . X . 5 O O X X . O . . | $$ | . . O , . . . . . , X X O O X O . . . | $$ | . . . . . . . . . . . O X X O . . . . | $$ | . . . . . . . . . . . 1 . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . X . O . . . , . . . . . , . . . | $$ | . . . . X O . . . O . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Bill Spight · Post by **Bill Spight** » Tue Sep 01, 2015 11:10 am

dangerdoom wrote:I played a game in which i pincered in the middle of a black formation and my pincer was surrounded on a bigger scale than I would have liked. I tried to pull the pincer stone (move 2) out with pretty bad results.

$$c
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 5 . . . |
$$ | . . . . O . . . X . . 2 . 1 a . 6 . . |
$$ | . . O , . . . . . b 7 . . . . O . . . |
$$ | . . . . . . . . . . . . . 3 . . . . . |
$$ | . . . . . . . . . . . . . . . 4 c . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . X . O . . . , . . . . . , . . . |
$$ | . . . . X O . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------

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

The continuation from the game is below. But my question is, if White doesn't pull the stone out, is the result okay?

Generally speaking, yes. In fact, an invasion like :w2:

is normally played with the idea of sacrificing it for sente and aji.

In this case, it is not clear that White should reply to :b5:

at

, because

weakens the effect of a White play at "a". Perhaps White should play at "b" instead, eschewing the sacrifice. OTOH, then the White group in the top right is weak. If White does not like the development after :w6:

at "b", perhaps he should not invade at :w2:

. After all, the simple keima at "c" is fine.

As the game went, :w8:

should simply extend on the right side. :w2:

still has aji.

Charles Matthews · Post by **Charles Matthews** » Tue Sep 01, 2015 12:42 pm

Bill Spight wrote:In this case, it is not clear that White should reply to at [...]

I agree with Bill, at least that the reply is too "automatic". Here at least is a thought process. If we ever get something like the top right corner here, there is a standard tesuji to cut.

Assume first the marked stones have been exchanged. Then we can see where the tesuji lies, with :w1:

,

. Black is clearly cut!

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

Now, to get realistic, where should White play if not at 3-3?

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

This

seems interesting. :b2:

tries to keep it all tight, but White is doing OK in this variation. There is something left at a; and the combination in the tesuji is still alive, I think.

Of course there are other variations.

gowan · Post by **gowan** » Tue Sep 01, 2015 3:20 pm

If White insists on trying to escape and Black insists on sealing White in, the following diagram might ensue:

Click Here To Show Diagram Code: [go]$$Wcm8 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . 7 . X . . . | $$ | . . . . O . . . X . . O 9 X 5 . O . . | $$ | . . O , . . . . . , X 8 1 3 4 O . . . | $$ | . . . . . . . . . . . . 2 X 6 . . . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . X . O . . . , . . . . . , . . . | $$ | . . . . X O . . . O . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

dangerdoom · Post by **dangerdoom** » Wed Sep 02, 2015 11:09 pm

Thank you for the replies. I see that the 3-3 move maybe went along with my opponent's plan too much.

ez4u · Post by **ez4u** » Thu Sep 03, 2015 2:13 am

If it is OK to invade and sacrifice the stone when Black has a 3-space extension (and we can find a variety of pro games like that), it can't be OK against a 4-space extension. indeed the examples in GoGoD of such invasions all have White putting the invading stone in motion instead of the 3-3 play. The most frequent choice is the simple 1-space jump but the shoulder hit and the knight's move jump have also been seen.

Life In 19x19

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