4-5 point 4-3 approach inside contact, follow-ups

  Difficulty: Expert   Keywords: Joseki
[Diagram]
Black has some aggressive plays  

Assuming White took sente at the end of this joseki, Black gets a chance to attack White.



According to the position as a whole, Black may wish to attack directly at the circle-marked point (a vital point of the diagonal of the white+circle stones); or to build influence with the cover at the square-marked point (discussed at order of play - temptation).

[Diagram]
Direct attack  

Suppose Black applies the direct approach B1. Then the pros usually come out at a. The play at b is a tesuji to help White gain immediate life.

[Diagram]
Standard fight  

After B4 here, the inducing move at W5 is taught as tesuji. It is possible for White simply to play at c'.

[Diagram]
Continuation  

This is a normal result: B1 at W2 will lead to nothing good for Black.


[Diagram]
A low position  

If instead W1, Black usually plays this way, treating White's play as submissive.

[Diagram]
A possible ko  

This is from a game Hashimoto Utaro-Suzuki Kensho (B), 1950-01-12. If B1 here, it makes no sense to go back later to the circled point to play hane, after Black has filled in a liberty. So we get B4. Now it can become ko.

[Diagram]
Game continuation  
[Diagram]
Game continuation  

There was no actual ko: White sacrificed the white+circle stones and in return weakened black+circle, as a big exchange happened.


[Diagram]
White is thick  

Simply playing W1 here gives White a high position, that is quite thick from fighting perspective. Later White can hope for White a, Black b as forcing.

[Diagram]
One line more  

If instead W1 here, White's shape is more efficient. But in this case Black can hope for a forcing exchange Black a-White b. That has an effect on any later white invasion at the circled point.



The tighter choice of W1 is therefore generally seen, in pro games.

Charles Matthews


4-5 point 4-3 approach inside contact, follow-ups last edited by DeaconJohn on January 17, 2011 - 16:59
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