Life In 19x19

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . |
$$ . . . . . . . . |
$$ . . . . . . . . |
$$ . . . . 1 . . . |
$$ . . . 4 , . . . |
$$ . . . . 2 3 . . |
$$ . . . . . a . . |
$$ . . . . . . . . |
$$ ----------------+[/go]

Why is not joseki? Does it give too much of the corner to black compared with "a"?

I think that if black nobies the only conceivable (or at least, not too passive) answer would be 6 in this diagram:

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . |
$$ . . . . . . . . |
$$ . . . . . . . . |
$$ . . . . 1 . . . |
$$ . . . 4 , 6 . . |
$$ . . . . 2 3 . . |
$$ . . . . . 5 . . |
$$ . . . . . . . . |
$$ ----------------+[/go]

Then, after 7 white has to defend the cuting point, and black gets profit in fourth line with 9, while white gets... well, A bit of aji and some influence towards the left. White probably needs to extend to the left now, but as black has a, b, etc., it doesn't look too valuable. In my opinion it doesn't seem even.

Click Here To Show Diagram Code

[go]$$B
$$ . . . . . . . . |
$$ . . . . . . . . |
$$ . . . . . . . . |
$$ . . b a 1 9 . . |
$$ . . . 4 7 6 . . |
$$ . . . 8 2 3 . . |
$$ . . . . . 5 . . |
$$ . . . . . . . . |
$$ ----------------+[/go]

First thought when opponent deviates from joseki: what happens if I play where he should have played? As salerno showed, this maxim works well here: that result is good for black.