Five stones on the third line in the corner

    Keywords: Life & Death
[Diagram]
Five stones on the third line in the corner  

This is the Five stones on the Third line in the Corner position and according to Segoe Kensaku's Go Proverbs Illustrated it is alive as it stands.

If it was not in the corner but on the side it would be the Five stones on the third line its status would depend on who moves first


Table of contents Table of diagrams
Five stones on the third line in the corner
Segoe's conclusion
The descent
A risky attack
A risky attack
A risky attack part 2
A risky attack part 3
After part 2
After part 2, my seq

Segoe's conclusion

[Diagram]
Segoe's conclusion  

Segoe's Go proverbs illustrated gives this diagram to show that this group is alive.

After W4 the group is undeniably alive. Depending on who plays next in this corner White lives with 4 to 5 points of territory

The Descent (bad for Black)

[Diagram]
The descent  

Another B1 is the descent but if white takes the vital point with W2 he is alive with more points.


The complicated way

[Diagram]
A risky attack  

If black attacks at B1 here, then white can make seki, or white can choose to fight a ko. Black may not want to risk starting a ko, because it could affect black's territory to the right. There are many complicated variations: see /discussion.

[Diagram]
A risky attack  

hnishy: Isn't it an unconditional life? a and b are miai.

kmr - looks like yes, as Segoe said in his book. However - if white play your move, then black can force seki (though allowing white to sneak into right). Or he can choose to shut white in, but then white has life with points. I will provide variations soon.

hnishy: the above was written on 23 Nov 2022. One week has passed...

kmr - sorry, i made mistake. Black cant force white to anything, its white choice. Thats why this attack with 1 is rather not good generally.

[Diagram]
A risky attack part 2  

kmr - If black 1 is answered with white 2, black has this sequence. Now white can choose between "a" (which gives ko for whole group after black play "c") and "b" (which results in seki when black plays "a", however then white can play "d" which destroys a lot of potentially black territory). This means black risky attack with 1 is not advisable, until black has stones close to "d" and can easily block it (loss on side is less than gain in corner). Instead of this 2, white can play this way:

[Diagram]
A risky attack part 3  

White parried black attack, living in seki, however black weakness at "a", "b" and "c" still exist.

[Diagram]
After part 2  

hnishy: White plays a clamp and escapes (or gets some more liberties and capture the corner).

[Diagram]
After part 2, my seq  

kmr - If black has enough stones close to "d" (as said before in diag named "A risky attack part 2"), white cant prevent seki if goes this way.

See also


Five stones on the third line in the corner last edited by kmr on December 2, 2022 - 08:25
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