Gokyo Shumyo, Section 1, Problem 26 / Solution

[Diagram]
White lives  
[Diagram]
Main line  

The tesuji here is W3. After W9, Black can't create a dead shape with a, because he is in shortage of liberties (this is oshitsubushi). Note what a difference a black stone on the marked point would make.

[Diagram]
Variation 1  

White has to be careful to answer B4 at W5 and not at W7. The strength of B3 is precisely that it already prevents the connection underneath.

[Diagram]
Variation 2  

Answering B4 at W5 is the only move. It appears as if White can destroy the eye after this sequence by throwing in again at B8, but White will simply connect at a.

[Diagram]
Variation 3  

Just to clarify: If Black tries to leave White with a big eye by connecting at a (almost filling the enclosed space with the dead shape of three in a line), White runs to b and claims a second eye at c.



How should White then respond if Black tries playing at d? That won't work for Black; White runs along the second line and if Black follows, eventually White can block on the first line and the resulting capture will give the second eye (at least). I don't think playing at e directly will work; seems like Black sets up a ko that way. White could probably also escape in this sort of situation. -- KarlKnechtel

[Diagram]
Variation 3  

There are many ways for White to go wrong. Let's assume she takes W1 as the obvious move, but fails to see the tesuji of W3 in the main line.

[Diagram]
Wrong 1  

Black's hane produces a ko


[Diagram]
Wrong 2  

Black kills with the same hane.

[Diagram]
Wrong 2 (variation by KarlKnechtel - there are some other similar ways too)  

[Diagram]
White lives?  

After B2, can white live?

xela: Yes, I think W3 at a works.

[Diagram]
White lives  

Why not the simple descent of W1? This makes miai of a and b, no?

xela: Black won't be kind enough to reply at B2, but will play c instead.


Problem 27
Back to KanazawaTesujiSeries


Gokyo Shumyo, Section 1, Problem 26 / Solution last edited by xela on December 10, 2008 - 06:28
RecentChanges · StartingPoints · About
Edit page ·Search · Related · Page info · Latest diff
[Welcome to Sensei's Library!]
RecentChanges
StartingPoints
About
RandomPage
Search position
Page history
Latest page diff
Partner sites:
Go Teaching Ladder
Goproblems.com
Login / Prefs
Tools
Sensei's Library