3-4 point high approach, two-space high pincer, ogeima

  Difficulty: Expert   Keywords: Joseki

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3-4 point high approach, two-space high pincer, ogeima, thrust 3-4 point high approach, two-space high pincer, ogeima 3-4 point high approach, two-space high pincer, ogeima, Kajiwara's variation
[Diagram]
Ogeima  

The large knight's move W1 here was invented by Fujisawa Kuranosuke. The most common continuation is at a, which will be further discussed on this page. There is also:



Main line

[Diagram]
Main line  

B6 here is by far the most common move. In the past, a and b have also been played, but a is now rare, b non-existent. White usually continues at c; white a is a variation that was long considered inferior, but is now accepted. White d has been played, but is now considered a mistake in order.

There is also Cho Chikun's variation where White plays W5 at c and Hashimoto Shoji's variation where Black plays B4 at W5.

[Diagram]
Main line (continued)  

The normal moves are as shown here, completing the joseki. For a while the relative timing of the W7/B8 and W9/B10 exchanges was considered a critical issue[1], W7 is now generally considered correct. B8 at a is a variant which is stronger in the corner, but is no longer played; the same holds for white forsaking the W9/B10 exchange and living with c. The exchange of W9 for B10 is a loss for White, as it greatly weakens the aji of his solitary stone, but it means that W11 indirectly covers the cutting point at b. B12 is of course not played if Black already has a stone in the area.

Variations

[Diagram]
Variation  

W11 in the previous line can here instead, provided the ladder works for White. The first time it appeared (perhaps) was in a game between Miyazawa Goro and Ishikura Noboru. Can the latter therefore be considered to have invented the variation ?

[Diagram]
Variation (continued)  

There are two issues in this joseki:

  • Will Black be able to make up for the local loss by playing effective ladder breakers for the ladder at a (which obviously works for White, or else she wouldn't play W11 in the previous diagram)?
  • Will Black be able to close off with b and cooperate well with the upper left ?

kokiri: also played by Nie weiping and discussed in his (unfairly criticised IMO) Nie Weiping On Go but in that example he used it to build a (black) position down the side.


Cho Chikun's variant

[Diagram]
Modern variant  

W5 is a modern variant of the joseki, known as Cho Chikun's variation. The variation shown here is currently most played, but there are several other, see the link.


Pushing in

[Diagram]
Pushing in  

W7 was long considered vulgar, but after AlphaGo seemed happy to play it, it is since considered joseki. The major turning point in this joseki is at B10. In this variation, black builds a strong wall, but white gets solid territory in the corner. White can continue at a to avoid being completely shut in, or play tenuki to counter the thickness black has built up.

[Diagram]
Direct cut  

If black does not want the result in the previous diagram, he can cut at B10 immediately. Black's thickness on the right side is less than before, but there is considerable aji left in the corner. The W15-B16 exchange is optional.


A fighting variation

[Diagram]
Black withdraws  

B1 is sometimes played, though much less than the main variation at W6. Play often reverts to the normal joseki through White W2, black W6, but either player can convert to this variation (black by playing B3 here, white by pushing in at W4 immediately with W2). What is shown here is one possible continuation.

[Diagram]
Continuation  

Both players put pressure on the right side, and it seems that White is winning there with W18, but B19 shows that Black has other plans.

[Diagram]
Continuation (2)  

Black captures five White stones, but White has two redeeming features. First and most importantly, she has sente, so Black has played a stone more in this corner, making his profit look actually quite small. Secondly, if she would get into trouble at the right side, there is always the option to connect with the corner starting at a.

Imagist I'm skeptical of this as joseki--there are a few spots in this where white simply plays at a in the diagram above and I can't find a way that B doesn't simply come up short on liberties.


Noseki

[Diagram]
Bad  

The cut at W2 is not good for White. If the ladder works for Black, he can cut at a to annihilate White. If not, he crosses under at b to give the following result.

[Diagram]
Bad: continuation  

This result is comparable to the one in Hashimoto Shoji's variation but it is worse. White's influence is diminished by the gaps at a and b.


The timing issue

[1]

[Diagram]
Critical line?  

This is a possible critical line for the supposed timing issue. W1 before W3 is natural, simply because W3 is locally a bad play, weakening the marked white stone (it is only played at all to strengthen White's cutting point). The question is, what if Black now plays B4 to cut, the shape to the right having been fixed by W1/B2?

This position has occurred in a game, Cao Dayuan vs. Sakata Eio 1987-04-27.

[Diagram]
One critical line  

After these plays and White a, Black b, White c, White has died inside and has much influence outside.

[Diagram]
Another critical line?  

Another possible critical line occurs when White pushes in the centre first, as here; and Black makes the bamboo joint B2 to thwart White's later play in the corner (now if White a, Black b and White has less eye shape). That invites W3 and induces the cut B4.

This was played in a Korean game (Seo Neung-uk vs. Cheong Su-hyeon 1990-12-07); variations are given in Jungsuk in Our Time.

[Diagram]
Another issue  

Another reason why White does not play at W1 first is shown here. An old variation of the joseki has Black answer W3 at B4, after which the moves to W7 follow. On itself this variation is now rejected for black, but it makes the W1-B2 exchange even worse for White.


AlphaGo innovation

[Diagram]
AlphaGo innovation  

Chris Hayashida: References coming. B1 is a novel answer to the ogeima. a and b are now miai.


See also


3-4 point high approach, two-space high pincer, ogeima last edited by ChrisHayashida on April 3, 2022 - 17:52
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