Xuanxuan Qijing Problem 130 / Solution

Shortage of liberties is the theme here.

[Diagram]
 

W1 is the key, B2 has to prevent W1 from escaping. After W5, black can't approach from either side. Alternatively, W5 at 'a' also works.

[Diagram]
 

If black plays B2 here, W3 W5 W7 does the same trick. Alternatively, 7 at 'a' also works.

[Diagram]
W3 in this diagram is not as good  

W3 in the previous diagram is better, because with ouside help, black can try to escape like this.

Failure

[Diagram]
Making atari with W1 doesn't work.  
[Diagram]
This atari doesn't work either.  

Don't play B4 at 'a', or white plays B4 and kills.

[Diagram]
 

If W1 black just secure the eye in the corner with B2. B2 at 'a' also works.

[Diagram]
 

After B2, the best white can do is getting a ko with x or y.



Don't get confused!!

It is important to notice where the outside liberties are. Let's look at this related problem.

[Diagram]
A similar problem  

'a' no longer works because of the liberty at 'x'. It won't be explained here but W1 at 'b' is the killing move for this black group.

[Diagram]
 

This is the original problem, do you see the difference?



Video

Without external liberty:
[ext] Life and death problem 001 on Michael Redmond's Go TV
With outside liberty:
[ext] Life and death problem 002 on Michael Redmond's Go TV


Xuanxuan Qijing Problem 130 / Solution last edited by PeterHB on June 22, 2020 - 05:27
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