Five stones on the third line in the corner
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This is the Five stones on the Third line in the Corner 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
More recent investigations is somewhat disputing Segoe's conclusion. But has not reached a final conclusion yet.
Everything here is therefore to be taken as research in progress not as final conclusions.
We start with an short overview of the most easy variations. under Old page pre WME more variations are found
Segoe's conclusion
Segoe's Go proverbs illustrated gives only this diagram to show that this group is alive.
After the group is undeniably alive.
But questions are raised about the first move in this sequence
(See also http://www.lifein19x19.com/forum/viewtopic.php?p=30778#p30778)
Depending on who plays next in this corner White lives with 4 to 5 points of territory
New research for move 1
The recent investigations attack with another
Directly to the 1-2 point
is at a vital point in this shape. White can try a lot of moves.
The most simple continuation that results in a living group is white c a move that leads to a seki in gote
for the variations following after a, b and d look at the old page below
White c results in a seki in gote.
We do not know if Segoe had this in mind. White is alive, but has lost his territory.
and to be honest it is a bit disapointed for White and so this is better for Black than Segoe's conclusion.
The Descend (bad for Black)
Although it is still uncertain if White needs to defend this shape followed by
are one way to do so. (there are other options)
Notice that if black plays continues with
and
White needs to defend on
or any of the points a because after
it is a rectangular eight in the corner
See also
-
Discussion over this shape with other variations on Life in 19 x 19
Please do not remove this diagram it is to create a empty line in the list of diagrams
Old page Pre WME
Below is the page from before the last main edit, it contains many more variations that are not jet integrated in the article above.
Go Proverbs Illustrated says that this shape is alive. Since I don't have the book, I'm not sure whether that means living with points or living in seki. What's the status of this group if Black plays first?
--MrTenuki
Go proverbs illustrated gives this explanation of how this group is alive.
(I only have this from ( hearsay)
fractic: I'm not a dan player but I've taken a look at this position. I think Black can get a ko or a seki. I would like a stronger player to take a look at this because some variations get rather complicated.
fractic: I think and
are the strongest resistance. Black can't play
at a because then white pushes out once more before playing b. So White can play a and play a ko. The ko is quite risky for Black too.
Anonymous: What happens if W plays directly at 'b' instead of setting up the ko? I spent a while with variations but can't find a way for B to kill.
fractic: Black descends with .
to Black a is one way to reach a ko or seki for white. I thought the previous diagram was stronger resistance because blocking with
is a bit unnatural but if White is allowed to push twice all the variations involving this descent don't work because white gets an extra liberty.
Note that if White makes seki now the count is 2 points better for Black than it would have been if Black had played hane tsugi at and
.
Anonymous: Yes, I considered the descent for B. But I couldn't find a refutation for . A couple of variations follow.
fractic: I think you are right. I just completely missed when I first analyzed this. Perhaps
is wrong..
Anonymous: The best defense I could find for W.
Andy Pierce: I think this is a stronger attack for black. There are lots of variations, but black can get a ko. It's often better to do the straight connected descent than to try the hane and owe a patch up move at the descent spot later.
xela: Can you show some variations? All I can see is seki.
fractic: I don't think works. White should take the vital point right away.
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