[go]$$Bc $$ ----------------+ $$ . . 6 1 7 3 2 . | $$ . O O X 4 X . 8 | $$ . . . O 5 X X 9 | $$ . . O . O X O 0 | $$ . . . . O O O . | $$ . . . . . . . . | $$ . . . . . . . . |[/go]
1. Standard way to live with this shape by expanding eye space 2. Key move aiming to remove the Q18 eye 3. Only way for black to protect 4. But now white has time to throw in 5-7. Black has no choice but to capture 8-0. Giving white the opportunity to fill all the outside liberties.
Re: 7k tsumego from a Japanese tsumego book
Posted: Sun Apr 01, 2012 6:06 pm
by tchan001
Good job Wildclaw. Actually the book solution ends with 3 and says something about Black living (althought it doesn't have the word seki anywhere in the explanation), but the sequence you have is the one I arrived at as well.
Re: 7k tsumego from a Japanese tsumego book
Posted: Sun Apr 01, 2012 8:34 pm
by Bill Spight
Wildclaw wrote:
tchan001 wrote:What is the status of the black group given the optimal sequence of play?
I am a bit out of shape, but I think the optimal sequence goes like this.
$$Bc $$ ----------------+ $$ . . 6 1 7 3 2 . | $$ . O O X 4 X . 8 | $$ . . . O 5 X X 9 | $$ . . O . O X O 0 | $$ . . . . O O O . | $$ . . . . . . . . | $$ . . . . . . . . |
[go]$$Bc $$ ----------------+ $$ . . 6 1 7 3 2 . | $$ . O O X 4 X . 8 | $$ . . . O 5 X X 9 | $$ . . O . O X O 0 | $$ . . . . O O O . | $$ . . . . . . . . | $$ . . . . . . . . |[/go]
1. Standard way to live with this shape by expanding eye space 2. Key move aiming to remove the Q18 eye 3. Only way for black to protect 4. But now white has time to throw in 5-7. Black has no choice but to capture 8-0. Giving white the opportunity to fill all the outside liberties.
White can usually omit , as it is gote. He can also probably save as a potential ko threat.
, as it is gote. 
He can also probably save 
as a potential ko threat.