Life In 19x19 :: Punishing joseki mistake (problem)

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Punishing joseki mistake (problem) http://prod.lifein19x19.com/viewtopic.php?f=15&t=1096	Page 1 of 2

Author: fwiffo [ Tue Jul 13, 2010 11:38 am ]

Post subject: Punishing joseki mistake (problem)

I had an opponent deviate from joseki, allowing a fairly severe punishment. I thought it might be an interesting problem for maybe 6k players.

Click Here To Show Diagram Code: [go]$$Bm1 $$ ------------------ $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . 3 4 6 . 2 . . $$ | . . O 5 1 . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Click Here To Show Diagram Code: [go]$$Bm7 $$ ------------------ $$ | . . . . . . . . . $$ | . . 6 a . 2 . . . $$ | . . X O O 1 O . . $$ | . 4 O X X 5 . . . $$ | . . 3 . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

is not joseki - it should be at a. Black to punish the error!

Author:	Chew Terr [ Tue Jul 13, 2010 12:15 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
Click Here To Show Diagram Code `[go]$$Bm7 b seems miai $$ ------------------ $$ \| . . . . . . . . . $$ \| . . 6 . b 2 B . . $$ \| . . X O O 1 O b . $$ \| . 4 O X X 5 . . . $$ \| . . 3 . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` Perhaps this?

Author:	fwiffo [ Tue Jul 13, 2010 12:24 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
Black can get more.

Author:	Magicwand [ Tue Jul 13, 2010 12:29 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
fwiffo wrote: Black can get more. i dont see any more. i am really curious how. Click Here To Show Diagram Code `[go]$$Bm7 are you talking about this? $$ ------------------ $$ \| . . . . . . . . . $$ \| . . 6 . 8 2 7 . . $$ \| . 0 X O O 1 O . . $$ \| . 4 O X X 5 . . . $$ \| . 9 3 . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]`

Author:	fwiffo [ Tue Jul 13, 2010 12:34 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
This is what I had in mind. Maybe I'm wrong? Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . 6 . . . . $$ \| . . O 2 1 O 5 . . $$ \| . 4 X O O X O 7 . $$ \| . O O X X X . . . $$ \| . 3 X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]`

Author:	CarlJung [ Tue Jul 13, 2010 12:42 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
fwiffo wrote: This is what I had in mind. Maybe I'm wrong? Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . 6 . . . . $$ \| . . O 2 1 O 5 . . $$ \| . 4 X O O X O 7 . $$ \| . O O X X X . . . $$ \| . 3 X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` Thats what I would have played.

Author:	amnal [ Tue Jul 13, 2010 12:46 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
fwiffo wrote: This is what I had in mind. Maybe I'm wrong? Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . 6 . . . . $$ \| . . O 2 1 O 5 . . $$ \| . 4 X O O X O 7 . $$ \| . O O X X X . . . $$ \| . 3 X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` Why not play 13 at 17? This is the normal way to play if you can, as white cannot answer differently so he ends up with worse shape.

Author:	fwiffo [ Tue Jul 13, 2010 12:52 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
I guess that is a little better. But the point is that white gets sealed in on both sides, which isn't possible in the joseki line.

Author:	topazg [ Tue Jul 13, 2010 1:57 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
amnal wrote: fwiffo wrote: This is what I had in mind. Maybe I'm wrong? Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . 6 . . . . $$ \| . . O 2 1 O 5 . . $$ \| . 4 X O O X O 7 . $$ \| . O O X X X . . . $$ \| . 3 X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` Why not play 13 at 17? This is the normal way to play if you can, as white cannot answer differently so he ends up with worse shape. Doesn't White end up with better shape this way? That looks like a failed A-B-C principle to me

Author:	amnal [ Tue Jul 13, 2010 2:03 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
topazg wrote: Doesn't White end up with better shape this way? That looks like a failed A-B-C principle to me It is not obvious to me that this is the case.

Author:	Magicwand [ Tue Jul 13, 2010 5:02 pm ]
Post subject:	Re: Punishing joseki mistake (problem)
they are both similar but bottom is the better answer by....fraction of a point. Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . O . . . . $$ \| . . O O . O X . . $$ \| . O . O O X O X . $$ \| . O O X X X . . . $$ \| . X X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . . . . . . $$ \| . . O . O O X . . $$ \| . O . O O X O X . $$ \| . O O X X X . . . $$ \| . X X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]`

Author:	HermanHiddema [ Wed Jul 14, 2010 1:14 am ]
Post subject:	Re: Punishing joseki mistake (problem)
fwiffo wrote: This is what I had in mind. Maybe I'm wrong? Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . 6 . . . . $$ \| . b O 2 1 O 5 a . $$ \| . 4 X O O X O 7 . $$ \| . O O X X X . . . $$ \| . 3 X . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` Black in the above diagram is not sente, should defend at a instead. All white gets is a move at capturing 2 stones in gote. Big endgame, nothing more (White will get b in sente later) Proper play: Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . . . . . . $$ \| . . O . 2 O 1 . . $$ \| . . X O O X O 3 . $$ \| . O O X X X . . . $$ \| . 4 X . . . . . . $$ \| . . 5 . . . . . . $$ \| . . . . . . . . .[/go]` This is proper play. White can choose not to play though, it is a push from behind on the second line, so it depends on the position whether it is good. White can wait anyway, a black move there is just large endgame, and currently gote.

Author:	entropi [ Wed Jul 14, 2010 1:51 am ]
Post subject:	Re: Punishing joseki mistake (problem)
Click Here To Show Diagram Code `[go]$$Bm7 $$ ------------------ $$ \| . . . . . . . . . $$ \| . . 6 . 8 2 7 . . $$ \| . 0 X O O 1 O a . $$ \| . 4 O X X 5 . . . $$ \| . 9 3 . . . . . . $$ \| . . . . . . . . . $$ \| . . . . . . . . .[/go]` In this diagram, wouldn't it be better to play white 16 at a, thus giving up two stones and avoiding being shut in?

Author:	Stable [ Wed Jul 14, 2010 2:29 am ]
Post subject:	Re: Punishing joseki mistake (problem)
That's what herman is saying I think entropi.

Author:	entropi [ Wed Jul 14, 2010 2:57 am ]
Post subject:	Re: Punishing joseki mistake (problem)
Stable wrote: That's what herman is saying I think entropi. Oops my question was already answered by an earlier post Sorry, I should have read it more carefully, I just looked at the diagrams.

Author:	Magicwand [ Wed Jul 14, 2010 3:01 am ]
Post subject:	Re: Punishing joseki mistake (problem)
Stable wrote: That's what herman is saying I think entropi. not really.. what herman is saying is ..16 & 17 exchange is an aji keshi that only helps black cover his weakness. although endgame point of view it is not optimal but in the opening part of the game it is better not playing optimally. black is not going to play 16 anytime soon because it is an aji keshi so there is no point playing endgame that only expose your weakness. 16-17 exchange will coverup the weakness at 'a' Click Here To Show Diagram Code `[go]$$Bm13 $$ ------------------ $$ \| . . . . . . . . . $$ \| . . O . 2 O 1 . . $$ \| . . X O O X O 3 . $$ \| . O O X X X . . . $$ \| . 4 X a . . . . . $$ \| . . 5 . . . . . . $$ \| . . . . . . . . .[/go]`

Author: HermanHiddema [ Wed Jul 14, 2010 3:16 am ]

Post subject: Re: Punishing joseki mistake (problem)

Magicwand wrote:

Stable wrote:

That's what herman is saying I think entropi.

not really.. what herman is saying is ..16 & 17 exchange is an aji keshi that only helps black cover his weakness. although endgame point of view it is not optimal but in the opening part of the game it is better not playing optimally. black is not going to play 16 anytime soon because it is an aji keshi so there is no point playing endgame that only expose your weakness.

16-17 exchange will coverup the weakness at 'a'

Click Here To Show Diagram Code: [go]$$Bm13 $$ ------------------ $$ | . . . . . . . . . $$ | . . O . 2 O 1 . . $$ | . . X O O X O 3 . $$ | . O O X X X . . . $$ | . 4 X a . . . . . $$ | . . 5 . . . . . . $$ | . . . . . . . . .[/go]

Actually, that was what I was saying in the text above my diagram.

Also, it's probably good to play this :w16:

exchange anyway, even though it removes aji, because otherwise:

Click Here To Show Diagram Code: [go]$$B $$ ------------------ $$ | . . . . . . . . . $$ | . . O . O O X . . $$ | . . X O O X C X . $$ | . O O X X X B . . $$ | . 1 X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

If black ever captures the white stone with :bc:

(e.g. white played a ladder breaker) then :b1:

becomes sente:

Click Here To Show Diagram Code: [go]$$B $$ ------------------ $$ | . . . 5 . 7 a . . $$ | 6 2 O . O O X . . $$ | . 1 X O O X C X . $$ | 3 O O X X X B . . $$ | . X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

Now, white can't ignore the capture :b3:

and play tenuki with :w4:

, because then :b5:

and

kill. As long as a is still atari (i.e. before the capture of white stone at :ec:

), black can't kill, but:

Click Here To Show Diagram Code: [go]$$B $$ ------------------ $$ | . . . 5 . . 6 . . $$ | 8 2 O . O O X . . $$ | . 1 X O O X O X . $$ | 3 O O X X X 7 . . $$ | . X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

This is a rather painful way to lose a ladder breaker.

So all in all, White should usually just play the :w16:

exchange in the original diagram, even though it is aji keshi a little.

Author: zinger [ Wed Jul 14, 2010 5:20 am ]

Post subject: Re: Punishing joseki mistake (problem)

Rolling back a few moves ...

Click Here To Show Diagram Code: [go]$$ $$ ------------------ $$ | . . . . . . . . . $$ | . . . . . O . . . $$ | . . X O O X O . . $$ | . 3 O X X 2 . . . $$ | . . 1 . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

When black plays 1, is it feasible for white to capture with 2? For ease of viewing it would look like this:

Click Here To Show Diagram Code: [go]$$ $$ ------------------ $$ | . . . . . . . . . $$ | . . . . . O . . . $$ | . . X O O . O . . $$ | . X . X X O . . . $$ | . . X . . . . . . $$ | . . . . . a . . . $$ | . . . . . b . . . $$ | . . . . . . . . .[/go]

True there is a loss in the corner, but white is much thicker than in the joseki. It seems like this might be playable in an approriate whole board position.

Next white can take sente to play elsewhere, or locally jump to a or even b.

Author:	Harleqin [ Wed Jul 14, 2010 5:29 am ]
Post subject:	Re: Punishing joseki mistake (problem)
I think that it is feasible, although the loss in the corner is quite big, so the sente has to be worth it.

Author:	fwiffo [ Wed Jul 14, 2010 5:32 am ]
Post subject:	Re: Punishing joseki mistake (problem)
Kogo's lists that as a joseki variation, but it's Kogo's.

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