Life In 19x19

I have read in The Basics of Go Strategy and seen in Hikaru no Go the following supposedly forcing sequence starting with to help construct a black moyo if white goes with in variation 1.

However, what should black do if white plays in variation 2?

Hi pragmatic,

Depending on the whole board, if B can fight,
B can follow up with his threat -- what's B's threat on ?

Hi EdLee,

EdLee wrote:Hi pragmatic,

Depending on the whole board, if B can fight,
B can follow up with his threat -- what's B's threat on ?

B was aiming at cutting in between white's two space extension, right?

However, if W S13 after B R12, doesn't black become heavy while white has at least one eye?

If B cut with R13 instead of R12, W S14 still give a similar result.

So far, I can only see B R15, W S15, B R13, W Q14, B S13, W S14 as being a reasonable result with white not quite securing one eye and black has sente, but if W S14 after B R15, would the continuation end in sente for white?

Are there other variations that are better for black?

Hi pragmatic,

pragmaticleas wrote:B was aiming at cutting in between white's two space extension, right?

Yes. If B cannot follow up with R12,
then your original shoulder hit has no bite.

pragmaticleas wrote:However, if W S13 after B R12, doesn't black become heavy while white has at least one eye?

Click Here To Show Diagram Code

[go]$$Wc
$$ -----------------------
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ . X . . . . . . X . . |
$$ . , . . . X . X . O . |
$$ . . . . . . . . . . . |
$$ . . . . . . O . O . . |
$$ . . . . . . . . . 1 . |
$$ . . . . . . . X X 2 . |
$$ . . . . . . . . O . . |
$$ . , . . . . . , . . . |
$$ . . . . . . . . . . . |[/go]

Locally, W has suffered a loss:
Please see toothpaste and related pages .

Globally, the evaluation depends on the whole board.
Re: post 2: Depending on the whole board,
if B can fight, then B can push through.

White will sometimes jump out as you showed to resist Black's shoulder hit in professionals' games, and black will then follow up on his threat and split and a fight follows. But you won't see the 1-2 exchange of the last diagram as that helps Black a lot. White at 2 in fact is a possibility. Also White's shape is not as good as you think: for example black can cut with the following sequence later if his 3 stones get stronger.

Click Here To Show Diagram Code

[go]$$Wc
$$ -----------------------
$$ . . . . . . . . . . . |
$$ . . . . . . . . . . . |
$$ . X . . . . . . X . . |
$$ . , . . . X . X . O . |
$$ . . . . . . . 8 4 5 . |
$$ . . . . . . O 6 O . . |
$$ . . . . . . . 7 . 1 . |
$$ . . . . . . . X X 2 . |
$$ . . . . . . . . O . . |
$$ . , . . . . . , . . . |
$$ . . . . . . . . . . . |[/go]

I would also change the emphasis of Ed's condition to: if white can fight then white can jump and allow black to split. In the diagram shown the fight is easier for black so it is white who should be nervous, she needs quite a bit of extra support to make this resistance reasonable. Once white jumps Black is pretty much obliged to split even if the fight isn't great or his previous move is useless.