Posts: 6727 Location: Cambridge, UK Liked others: 436 Was liked: 3720
Rank: UK 4 dan
KGS: Uberdude 4d
OGS: Uberdude 7d
|
First point, I think you got 2 and 4 in wrong order for setup diagram:
- Click Here To Show Diagram Code
[go]$$B $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 4 . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 3 . O . . . . . , . . . . . , . . . | $$ | . . 1 2 . . . . . . . . . . . . . . . | $$ | . 7 . 5 6 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
Secondly, here is the basic idea of how to live without ko due to weaknesses in white's surrounding stones. (There are more sophisticated ways, e.g. play 4 at 6 first):
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 9 . . . . . . . . . . . . . . . . | $$ | . O 8 O . . . . . . . . . . . . . . . | $$ | 7 6 0 . . . . . . . . . . . . . . . . | $$ | 5 X . O . . . . . , . . . . . , . . . | $$ | 3 . X O . . . . . . . . . . . . . . . | $$ | 4 X 2 X O . . . . . . . . . . . . . . | $$ | . . . 1 . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
(variation: if 9 ataris from other side then at a minimum white can live with 12 throw in as below, may even be able to extend from 10 depending on side position)
- Click Here To Show Diagram Code
[go]$$Wm9 (7 connects at 4) $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 8 . . . . . . . . . . . . . . . . . | $$ | 5 3 2 . . . . . . . . . . . . . . . . | $$ | 4 O X O . . . . . . . . . . . . . . . | $$ | O X 1 . . . . . . . . . . . . . . . . | $$ | O X . O . . . . . , . . . . . , . . . | $$ | O 6 X O . . . . . . . . . . . . . . . | $$ | X X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm11 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . 1 O 5 . . . . . . . . . . . . . . . | $$ | . O X O 4 . . . . . . . . . . . . . . | $$ | O X X 2 3 7 . . . . . . . . . . . . . | $$ | O X . O 6 . . . . , . . . . . , . . . | $$ | O . X O 8 . . . . . . . . . . . . . . | $$ | X X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
So it is not so accurate to say this corner is unconditionally alive, as such phrases are normally used to refer to locally enclosed shapes. It would be more accurate to say it is alive due to weaknesses in the surroundings. As some exercises, is it alive when white has the following reinforcement? This is actually a quite common strategy in real games, to get one of these reinforcement stones in sente against some other group you are attacking which would then allow you to kill the corner.
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . W . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . O . . . . . , . . . . . , . . . | $$ | . . X O . W . . . . . . . . . . . . . | $$ | . X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . W , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . W . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . W . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . X . O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm1 $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . O . O . . . . . . . . . . . . . . . | $$ | . . . W . . . . . . . . . . . . . . . | $$ | . X . O . . . . . , . . . . . , . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X X X O . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ +---------------------------------------+[/go]
|
|