Short J Group

    Keywords: Life & Death
[Diagram]
Short J group  

The short J group is actually a tripod group followed by the white+circle- black+circle exchange. It is alive as it stands. A White stone around a makes it unsettled, however. Playing black+circle at b is a wrong and leaves the group unsettled.

It should not be confused with the J group.


Table of contents Table of diagrams
Short J group
Attemp 1
Attemp 2
Attemp 3
Attempt 4
Attempt 4, alternative
Mistake after follow-up 4
Straight Short J group
[Short J group with extra leg]
An extra White stone on the upper side
continuation
Index of sub-pages

Alive

[Diagram]
Attemp 1  

If W1 blocks, then B2 lives. Black has (on average) 4 points of territory.

[Diagram]
Attemp 2  

If W1 makes a placement here, then B2 hanes. W3 and B4 are miai for life.

[Diagram]
Attemp 3  

The descent at W1 is answered by B2 as well. Black has only 2 points of territory, the best result for White.

[Diagram]
Attempt 4  

W1 and W3 is probably the strongest attack, threatening a ko. The throw-in at B4 is neccessary for life. The result is oshitsubushi.

[Diagram]
Attempt 4, alternative  

If W5 captures, then B6 and B8 lives by oshitsubushi as well.

[Diagram]
Mistake after follow-up 4  

B4 here would be a mistake, because W5 turns the whole group into a ko.


The straight Short J group

[Diagram]
Straight Short J group  

If black+circle is as in this diagram (instead on a) as before than white can kill with the eye-stealing tesuji of W1, making a placement and aiming at setting up a snapback at b. Black is dead.


Short J group with extra leg

While the short J group is alive black must be careful not to play the B1 - W2 exchange and then play tenuki the group now becomes unsettled see Short J group with extra leg for details


An extra white stone on the upper side

[Diagram]
An extra White stone on the upper side  

Black must also be careful when White has played at white+circle if he does nothing While can kill him with White a

TO ADD what is blacks best defence

If White has a stone at at b white needs to play a (see attempt 1 above)

TO ADD what about White c

[Diagram]
continuation  

After white+circle, W1 and W3 reduce the corner to one eye and although W5 can be captured (Black a White b it is only a false eye.



This page is mostly coming from the page of the tripod group I is because another page the tripod group with extra leg is not really a tripod group at all. It is a short J group (with an extra leg)


Short J Group last edited by hnishy on May 25, 2018 - 13:25
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