Jfc 001 / Solution

Sub-page of Jfc001
[Diagram]
Black dies  

Unfortunately it looks like that, without reinforcement, White can get Black's eye down to the bulky five shape. So Black is dead if White goes first.


[Diagram]
Black gets a ko.  

Black has four internal ko threats (a, b, c and d) here, while White has none at the moment. So she will not try to kill by this method immediately, if this is the only way. White will play very insolently in other parts of the board, accumulate some ko-threats, and then will return here.

-- HolIgor
[Diagram]
More ko threats?  

I think Black has even more internal ko threats (starting at a) by playing the ko immediately as in this diagram. On the other hand, playing the descent immediately will avoid giving White two moves somewhere, so Black might want to play defensively immediately after all. -- Andre Engels


[Diagram]
Weird sequence?  

Jasonred I'm a very dumb Go player, I don't see how White stops Black living with a ladder. You smart players, you teach Grimlo... errr, Jasonred?

Actually, I think W7 is the wrong response. Should it go B6, White a, B7, White b, Black c? But that looks like an even worse outcome for White?

unkx80: W7 should play at c.

[Diagram]
Now what?  

Jasonred : Now what? Is white+circle a possible eye for Black? If so, how does White stop Black getting it? Can't Black manage one more eye somewhere? I'm hopeless, but it looks to me like a reasonable number of liberties, and enough space... come to think of it, is white+square a possible eye?


Bill: Jonathan's original question was about the status of Black's group in the top left corner. Black can live with one net play, while White can kill in two, if White is komaster. Otherwise, since White loses more by making and losing the ko instead of just allowing Black to live in gote, White may just make Black live small in sente. So we can say that the group is more than 2/3 alive. ;-)

Even if White could win the ko, it would be worth only around 10 points, miai counting. Since it is Black's move, he should tenuki.


Also note that if White had connected below W5 with W7, she would have allowed Black to live by playing at W7.

[Diagram]
Black dies  
[Diagram]
Black dies  

With W8 at W4, Black is gone.

[Diagram]
Black lives  

Here, Black definitely lives. --FCS B3 is not needed? Too small?

[Diagram]
Black lives, but with one less point  



Hikaru79: I think that the diagram does not end there. W7 must not be ignored, or the following happens:

[Diagram]
Seki?  

Due to blacks outside liberty, this is not a seki. Black can play atari and live unconditionally.

unkx80: Without W9, it is seki.


Jfc 001 / Solution last edited by Unkx80 on April 22, 2005 - 19:32
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