Life In 19x19

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

I've seen played as a response to several times on Tygem. My answer has always been to play at (a) forcing white to live small and gaining a nice wall. Has anyone else encountered this, and if so how have you answered this move?

If you've seen any other moves that you suspect to be non-joseki, post them here for discussion.

I don't think it's necessarily a mistake (locally speaking, anyway). However, it is very uncommon, as GoGoD has this position occurring only 15 times out of the 9878 times it occurs. Your move is a pretty common response, as is just taking the 3-3 (and reverting to another joseki).

Dusk Eagle wrote:GoGoD has this position occuring only 15 times out of the 9878 times it occurs

I know what you meant, but...

Yeah, I reread that and I tried to edit it before anyone noticed . You're too quick.

Dusk Eagle wrote:I don't think it's necessarily a mistake (locally speaking, anyway). However, it is very uncommon, as GoGoD has this position occurring only 15 times out of the 9878 times it occurs. Your move is a pretty common response, as is just taking the 3-3 (and reverting to another joseki).

Does GoGoD only contain pro games? I'd be very surprised to see this in a professional game, perhaps you can supply some of the game records to satisfy my curiosity?

It seems black can revert to this joseki if thickness is desirable (normal move order being 1 2 5 4 3, bug Emerus about it if you're curious, I know he likes this one). I dunno if he can place 5 more optimally as a "punishment".

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

Edit; I guess I'll add what we're all thinking, is this sort of variation possible-

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[go]$$Bc (Followed by a white counterattack on 3 of some kind)
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

Loons wrote:Edit; I guess I'll add what we're all thinking, is this sort of variation possible-

$$Bc (Followed by a white counterattack on 3 of some kind)
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |

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[go]$$Bc (Followed by a white counterattack on 3 of some kind)
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

This kind of thing is fine, in principle, though I'd be inclined to be a little tighter with placing 7, so that I could fight harder. I think I've seen before that 4 is what books list as a mistake because it doesn't really help the white group but it gives black the corner (whereas in the normal joseki white might find it convenient to take the corner later).

I think it's only a minor thing really, as evidenced by the fact that pros have played it ever at all .

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . a . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

I like this sequence, but I disagree with amnal that would be better at (a). In the normal joseki

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

black plays at instead of (a) because if B(a) then will be at . Later, white can invade the corner . Black would prefer his shape to be , and (a), in my opinion. With that said, I'll try this sequence if it comes up again.

mw42 wrote:

$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . a . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |

Click Here To Show Diagram Code

[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . a . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

I like this sequence, but I disagree with amnal that would be better at (a). In the normal joseki

$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . 6 . . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . , . . . . . |
$$ . . . . . . . 3 . . |
$$ . . . . . . . a . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |

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

black plays at instead of (a) because if B(a) then will be at . Later, white can invade the corner . Black would prefer his shape to be , and (a), in my opinion. With that said, I'll try this sequence if it comes up again.

I don't think 'in the normal joseki' is really a good way to think about things, because our situation is significantly different.

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . 7 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

Looking at it like this, I think that 5 is well placed becasue white doesn't have time to pincer as his stones are lacking in eyespace. It feels like 5 will make it harder for white to settle, and certainly 5 is standard shape to make here. That, plus I am too tenacious for my own good . This move is what I meant by 'tighter'.

To clarify, I think both are fine and there seems to be good reasoning behind them. I am not convinced by the 'normal joseki' reasoning, though.

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . b a . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

There was a double misunderstanding. When you said "tighter" I thought you meant (a), but you meant (b). Both (b) and would be good moves here. I think (a) is sub-optimal compared to for the explanation I gave above.

One thing I noticed when browsing through all the games just now is that white almost always has a strong position along the right side when white plays , making it so that black is cramped along the right. So it very well could be mistake otherwise.

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . . . . |
$$ , . . . . . 1 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . O O . . |
$$ , . . . . . O X . . |
$$ . . . . . . . . . . |[/go]

Anyway, here are two games where it occurs:

[sgf-full]http://lifein19x19.com/forum/download/file.php?id=824[/sgf-full]

[sgf-full]http://lifein19x19.com/forum/download/file.php?id=825[/sgf-full]

P.S. Although the player who plays this variation loses both of the games above, the actual win/loss record for this corner position is right around 50%.

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . b a . . |
$$ . . . . . . . 7 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

Regarding this diagram, I think a is better in most cases. Look at it this way:

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . 7 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . . 5 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

5 is a move played very commonly in this joseki. If 6 is played I would almost certainly answer with 7, so I can't see how the large knight's move would be better.

Or if we do some tewari... is clearly terrible, but is only perhaps a little too close.

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 7 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . 3 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

I think a better tewari analysis is this. 6 is a little aji keshi as it removes the possiblity of a 3-3 invasion.

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[go]$$Bc
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . 7 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . . 5 . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ , . . . . . , . . . |[/go]

I also want to claim the "skim the thread more thoroughly before posting award", as this diagram has been posted like a dozen times ...

One question is why is the following not joseki:

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[go]$$B Variation 1
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 6 . . . |
$$ . . 3 . 2 . . 7 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 4 . . . . . |
$$ . . . . . . 5 . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]

A joseki move for is not the keima (a), but the shoulder hit:

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

One reason, as Redundant noted, is W(a) is aji-keshi.

The following is also not joseki:

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

Or, at least is a rare move. One reason is B is a little thin.

However, if W does the exchange:

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[go]$$B Variation 3
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . . . 4 . . . |
$$ . . 3 . 2 . . 5 . . |
$$ , . . . . . 1 . . . |
$$ . . . . 6 . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . 7 . . . |
$$ . . . . . . . . . . |[/go]

Then B can jump to -- this may pertain to amnal wanting to be "tighter."

Another idea , if the ladder works for B -- next if W(b), B can extend to (c):

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[go]$$W Variation 4
$$ --------------------+
$$ . . . . . . . . . . |
$$ . . . . 7 3 1 . . . |
$$ . . X 6 O 2 . b . . |
$$ , . . 5 4 . X 9 . . |
$$ . . . 8 . . . 0 c . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |
$$ . . . . . . . . . . |[/go]