Life In 19x19
http://www.lifein19x19.com/

tsumego, maeda, elementary #87
http://www.lifein19x19.com/viewtopic.php?f=15&t=6446		 Page 1 of 1
Author:  cyclops [ Sun Aug 05, 2012 4:50 pm ]
Post subject:  tsumego, maeda, elementary #87
This problem took me too much time. After I solved it I wondered why it was so difficult. Well, to make up for the time spent, I publish it here on L19.
Click Here To Show Diagram Code
[go]$$Bc Black to play ~7kyu
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . , . X . . |
$$ | . . . . . . . . . |
$$ | . . , . , O O . . |
$$ | . . . O O X O . . |
$$ | . . , O X X X . . |
$$ | . . . O O X . . . |
$$ | . . . . . . . . . |
$$ +-------------------+[/go]

Hidden: Book solution
Click Here To Show Diagram Code
[go]$$Bc Solution from book
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . , . B . . |
$$ | . . . . . . . . . |
$$ | . . , . , O O . . |
$$ | . . . O O X O 2 . |
$$ | . . , O X X X . . |
$$ | . . . O O X . 1 . |
$$ | . . . . . . 3 . . |
$$ +-------------------+[/go]
What took me so long was to refute :w2: at 3. OC the distant black stone will play it's role.
Hidden: refutation of variation
Click Here To Show Diagram Code
[go]$$Bc
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . , . X . . |
$$ | . . . . . . . . . |
$$ | . . , . , O O 4 8 |
$$ | . . . O O X O 3 5 |
$$ | . . , O X X X 9 b |
$$ | . . . O O X . 1 6 |
$$ | . . . . . 7 2 a . |
$$ +-------------------+[/go]

Because of G7 :b3: forces :w4: .
After the diagram W only can make a gote seki at a. So B lives.
For me it was hard not to play :b5: at b.

Hide: Then why doesn't work :b5: at J3 in the last diagram?
Click Here To Show Diagram Code
[go]$$Bc
$$ +-------------------+
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ | . . , . , . X . . |
$$ | . . . . . . . . . |
$$ | . . , . , O O 4 8 |
$$ | . . . O O X O 3 c |
$$ | . . , O X X X . X |
$$ | . . . O O X . 1 . |
$$ | . . . . . 7 2 6 a |
$$ +-------------------+[/go]

After this diagram w can choose between a and c to make ko. No idea which is better.


edit: added another section. I hope CnP likes it better!
Author:  CnP [ Mon Aug 06, 2012 3:09 pm ]
Post subject:  Re: tsumego, maeda, elementary #87
I'm doing this set but that problem was no use for me. I'm also studying All about life and death and that problem is literally a textbook example of how knowledge of L groups speeds up finding the solution apparently. Sadly I remembered it when I came to it in this set so I couldn't test myself on it
Page 1 of 1 All times are UTC - 8 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/