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SecondCourseOnKo

Referenced by
Jfc001

 

Solution To Jfc 001
Path: SecondCourseOnKo   · Prev: HolIgorMeetsTripleKo   · Next: SquareNineInTheCorner
    Keywords: Ko

[Diagram]
Diag.: 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]
Diag.: 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]
Diag.: 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 sagari immediately will avoid giving White two moves somewhere, so Black might want to play defensively immediately after all. -- Andre Engels



[Diagram]
Diag.: Weird sequence?

Jasonred Hi, me is very dumb Go player, me not see how White stop Black live with ladder. You smart players, you teach Grimlo... errr, Jasonred?

Un-dino-bot-mode... Actually, I think 7 is the wrong response. Should it go Black 6, White a, Black 7, White b, Black c? But that looks like an even worse outcome for White?

unkx80: White 7 should play at c.


[Diagram]
Diag.: Now what?

Jasonred : Now what? Is the circled stone 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 the squared spot 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. Since it is Black's move, he should tenuki.


Also note that if White had connected below 5 with 7, she would have allowed Black to live by playing 7.

[Diagram]
Diag.: Black dies

[Diagram]
Diag.: Black dies

With White 8 at 4, Black is gone.


[Diagram]
Diag.: Black lives

Here, Black definitely lives. --FCS Black 3 is not needed? Too small?



Path: SecondCourseOnKo   · Prev: HolIgorMeetsTripleKo   · Next: SquareNineInTheCorner
This is a copy of the living page "Solution To Jfc 001" at Sensei's Library.
(OC) 2003 the Authors, published under the OpenContent License V1.0.