6

In a game my opponent deviated from the joseki line I was familiar with.

$$W Actual game
$$ ------------
$$ -...........
$$ -.94........
$$ -.5128O.....
$$ -..X36...0,.
$$ -...7.......
$$ -...........
$$ -...........

Instead of B10, I expected this exchange first:

$$B Expected
$$ ------------
$$ -...........
$$ -.OX........
$$ -.OOXXO.....
$$ -..XOX1..3,.
$$ -...O.......
$$ -...........
$$ -...2.......

The result here appears to be even to me, white is a little better locally but she played first so it is to be expected.

Since black omitted the 1-2 exchange and played 3 directly, he seems to plan on letting the sole white stone die on a larger scale. Consequently it appears natural to use this stone to punish black's deviation.

I've got three basic ideas how to:

  1. Tenuki and leave the bad aji. Omitting W2 as a securing move should be fine since black can't fight properly without swallowing the sole white stone first.

  2. Play W2 regardless. Then black has 2 options: play B1 so it reverts to the known pattern, or tenuki - in that case white can move her stone out easily and fight, so black probably won't do that. However, since B3 is not joseki as far as I know, this would be too easy on black.

  3. Move W2 out, splitting black's stones.

I'm thinking of either this attachment:

$$W Attachment and keima
$$ ------------
$$ -...........
$$ -.OX........
$$ -.OOXXO.....
$$ -..XOX..1X,.
$$ -...O....2..
$$ -.....3.....

or this shape:

$$W Attachment and sake bottle shape
$$ ------------
$$ -...........
$$ -.OX........
$$ -.OOXXO.12..
$$ -..XOX...X,.
$$ -...O..3....
$$ -...........

Option 3 seems to induce black to make white's left side group stronger, but at the same time, black's top stone gets stronger as well.

Is any of my ideas here reasonable? Or is black's "deviation" in fact a joseki, too?

2
  • I know this is ancient history, but is Oogeima a misspelling of Ogeima? Or is this an alternative romanisation? At any rate, Sensei does not have an article Oogeima! Also you write derived where you presumably mean deviated.
    – PJTraill
    Commented Apr 12, 2018 at 18:41
  • @PJTraill Thanks, fixed. As for Oogeima, I believe both are commonly seen. The Japanese word starts with "大" (large) which is read as "oo" here.
    – mafu
    Commented Apr 12, 2018 at 21:38

3 Answers 3

5

1 and 2 are "honte" moves. They result in solid positions as they remove all aji from the marked stones, but are not mandatory.

$$cm1
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O O X X Q . . . . . . . . . . . . . |
$$ | . . B O X 1 . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . | 

If black has a strong position in the upper right, she'll welcome a fight that will allow to build while attacking.

$$cm1
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O O X X O . . . . . . . . . B . . . |
$$ | . . X O X . . . 1 . . . . . . . . . . |
$$ | . . . O 3 . . 2 . . . . . . . . B . . |
$$ | . . . 4 5 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . | 

So omitting F16 in this case seems reasonable, and white can't really punish black, at least not before reinforcing her own shape.

As often with joseki, it is difficult to analyze the moves here without seeing the context.

[Update] I browsed pro games that include this pattern, and it confirms that black doesn't need to play F16. Even after white plays D13 or D14, black might tenuki. If white doesn't reinforce the area, then later black might opt for a more aggressive move, like E14 or D13.

$$cm1
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O O X X O . . . . . . . . . . . . . |
$$ | . . X O X . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . a . . . . . . . . . . . . . . |
$$ | . . . b . . . . . . . . . . . . . . . | 
4

W1 seems like a good move to me. B can't get a rhythm to fight well even if he ignores it to make something happen. I may be wrong but B's deviation looks like a gross overplay to me. I can't see W playing a "solid be get better result" so starting a fight seems good for W.

The only other option I can think of, other than W1, is the 5th line shoulder hit which is worth thinking about. It's much harder to control and more easily ignored though.

$$W 5th line shoulder hit
$$ ------------
$$ -...........
$$ -.OX........
$$ -.OOXXO.....
$$ -..XOX...X,.
$$ -...O...1...
$$ -...........
1
  • The shoulder hit seems to lead to pretty complicated fighting and several semeai possibilities on the edge. Just as you said, really difficult to judge. I guess if black were to just push and connect by clamp it would be too submissive.
    – mafu
    Commented Jan 18, 2012 at 18:06
3

The attachment is fine but B will resist in a different way, I guess (maybe pushing?).

$$W Attachment, black resists
$$ ------------
$$ -...........
$$ -.OX........
$$ -.OOXXO.....
$$ -..XOX..1X,.
$$ -...O2......
$$ -...34......
$$ -...........

In the (expected) variation move 2 shouldn't be a jump, rather a nobi (extension) to get a more solid shape, then I agree that W is better.

$$B Expected, stronger shape
$$ ------------
$$ -...........
$$ -.OX........
$$ -.OOXXO.....
$$ -..XOX1..3,.
$$ -...O.......
$$ -...2.......
$$ -...........
0

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .