Tryphon wrote:
It's a simple sequence whose brothers occurs quite often (I know there are better sequences for W, but let's keep this one for the sake of simplicity).
I'm black. I'm glad to push forward, keep W low, make a wall that goes well with the top hoshi stone. I could do that up to the right edge
At first I thought that you were asking about White's play. White is
pushing, Black is
extending.
It is well known that building a wall on the fourth line facing the center is better (on an empty board) than building a wall on the third line facing the edge. Every time that you let White push you you are gaining points (unless White needs to secure his group).
Quote:
But at a moment, I'd like to play around a because if W does, he neutralizes the wall.
This is a common amateur misconception. A single play, even on the ideal point, cannot neutralize a strong wall. Already Black's wall is too strong.
Quote:
When is the good moment for that, and where to play ?
- Click Here To Show Diagram Code
[go]$$Bm1
$$ +------------------------
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . X . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . 5 . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . X . . . . . . . .
$$ | . . . , . X X X 1 3 . .
$$ | . . . . O O O O . 2 4 .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ +------------------------[/go]
A 5 space extension is about as far as you can go. You do not want to leave White room for a regular base.
- Click Here To Show Diagram Code
[go]$$Bm1
$$ +------------------------
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . X . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . 5 . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . 6 , . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . 7 . . . . . . . . .
$$ | . . a . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . X . . . . . . . .
$$ | . . . , . X X X 1 3 . .
$$ | . . . . O O O O . 2 4 .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ +------------------------[/go]
is inefficient, too close to the wall. But if Black does not pincer from this side, White has room to make a base with a play at "a".
Quote:
I'd like too to play around b. Is it a good idea ?
- Click Here To Show Diagram Code
[go]$$Bm1
$$ +------------------------
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . 1 . . . . . b . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . a . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . 3 . . . . . . . .
$$ | . . . , . 5 7 9 . . . .
$$ | . . . . 4 6 8 0 . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ +------------------------[/go]
Not as good as "a".
----
BTW:
- Click Here To Show Diagram Code
[go]$$Bm1
$$ +------------------------
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . X . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . 3 . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . 2 . . . . . . . .
$$ | . . . , . . . . . , . .
$$ | . . . . . . . . . . . .
$$ | . . . 4 . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ | . . . X . . . . . . . .
$$ | . . . , . X X X 1 . . .
$$ | . . a . O O O O 5 . . .
$$ | . . . . . . . . . . . .
$$ | . . . . . . . . . . . .
$$ +------------------------[/go]
The turn at
is bigger than it looks. Even without the threat to play at "a".
I was taught that it is as big as an enclosure. Now I think that it is usually not quite that big. (In this case it is, because of "a".)