L+2 Group / Discussion

Sub-page of L2Group
[Diagram]

First hane

aLegendWai: How about if B2 plays at a? Will it live? If both can make w live, which is better and why? Thanks for the answer.



unkx80: The following two diagrams should show the difference.

[Diagram]

First hane

[Diagram]

First hane


[Diagram]

Second hane: failure

Answering this hane at 1-2 leads to disaster. Black can't play 8 at a because of shortage of liberties. If Black 6 at a, White 7 at 6 kills: see rectangular six in the corner.

I may be missing the bleeding obvious here - but doesn't Black 6 at 7 give life for black?


RichardHunter: A Japanese book I have says this B2 also lives but is thin. The reason is at both b and c are sente, which is not the case if Black plays the 2-2 point as above.

Bill: I set up a difference game, but the advantage of the 2-2 is not so clear to me.

[Diagram]

Difference game

For instance, B1 threatens to kill, but W2 protects the group. Now Black would have an advantage if he could play B3 with sente, but White plays W4, probably leading to mutual damage.




[Diagram]

Answer

Good question. If B1 here, White makes a bulky five inside Black's eyespace. Black can not play at a because of shortage of liberties. What I said is wrong !! --Dieter

Dieter -- black will not play at a, but capture -- white 4 is a snapback. I still see this as black lives. Dieter: Yes I noticed, but didn't have the time to re-edit my stuff. Hence the exclamation above.


[Diagram]

Second hane: failure?

Bill: How about B 6? Dieter: see above (though you were first). Maybe a white stone at b is appropriate to prevent escape. WRONG. Needs edit Dieter

[Diagram]

Second hane: failure?

[Diagram]

Snapback


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