Life In 19x19 :: Tesuji Problem

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Tesuji Problem http://www.lifein19x19.com/viewtopic.php?f=15&t=4639	Page 1 of 1

Author: lightvector [ Sun Sep 11, 2011 10:04 am ]

Post subject: Tesuji Problem

I have a question about a tsumego. In Davies' book "Tesuji", the following problem is given, with the following solution.

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

But what if white responds this way?

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

I'm having difficulty reading this out. Can black capture white from here? There are a lot of variations where white gets into a capturing race with the corner. And there's also the problem that unless black spends a whole move to defend D7, white can escape there if he ever has at least 3 liberties on his turn.

Author: daal [ Sun Sep 11, 2011 11:01 am ]

Post subject: Re: Tesuji Problem

lightvector wrote:

But what if white responds this way?

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

Seems to me that b1 catches black.

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

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

Click Here To Show Diagram Code: [go]$$c $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | 7 3 X . . . . . . . . . . $$ | . 2 O . X . . . . . . . . $$ | 6 1 O O O X X . . . . . . $$ | . 4 X X X O . . . . . . $$ | . 5 X O O O . O . . . . . $$ | . . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

Author:	Joaz Banbeck [ Sun Sep 11, 2011 11:05 am ]
Post subject:	Re: Tesuji Problem
daal wrote: ... Click Here To Show Diagram Code `[go]$$c $$ \| . . . . . . . . . . . . . $$ \| . . O O X O . . . . . . . $$ \| . . . . O . . . . . . . . $$ \| 7 3 X . . . . . . . . . . $$ \| . 2 O . X . . . . . . . . $$ \| 6 1 O O O X X . . . . . . $$ \| . 4 X X X O . . . . . . $$ \| . 5 X O O O . O . . . . . $$ \| . . X X O . . . . . . . . $$ \| . . . . . . . . . . . . . $$ --------------------------[/go]` Click Here To Show Diagram Code `[go]$$c $$ \| . . . . . . . . . . . . . $$ \| . . O O X O . . . . . . . $$ \| . . . . O . . . . . . . . $$ \| 7 3 X 8 . . . . . . . . . $$ \| . 2 O 9 X 0 . . . . . . . $$ \| 6 . O O O X X . . . . . . $$ \| . 4 X X X O . . . . . . $$ \| . 5 X O O O . O . . . . . $$ \| . . X X O . . . . . . . . $$ \| . . . . . . . . . . . . . $$ --------------------------[/go]`

Author: emeraldemon [ Sun Sep 11, 2011 11:15 am ]

Post subject: Re: Tesuji Problem

seems like :b7:

has to be here:

Click Here To Show Diagram Code: [go]$$Bcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | . 3 X 7 . . . . . . . . . $$ | . 2 O . X . . . . . . . . $$ | 6 1 O O O X X . . . . . . $$ | . 4 X X X O . . . . . . . $$ | . 5 X O O O . O . . . . . $$ | . . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

looks like maybe a ko? I agree it seems very complicated.

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | 8 2 . . O . . . . . . . . $$ | 1 X X X . . . . . . . . . $$ | . O O . X . . . . . . . . $$ | O . O O O X X . . . . . . $$ | 5 O X X X O . . . . . . . $$ | 4 X X O O O . O . . . . . $$ | 7 . X X O . . . . . . . . $$ | . 6 . 3 9 . . . . . . . . $$ --------------------------[/go]

Author:	Shaddy [ Sun Sep 11, 2011 11:39 am ]
Post subject:	Re: Tesuji Problem
Click Here To Show Diagram Code `[go]$$Bcm1 $$ \| . . . . . . . . . . . . . $$ \| . . O O X O . . . . . . . $$ \| . . . . O . . . . . . . . $$ \| 7 3 X . . . . . . . . . . $$ \| 5 2 O . X . . . . . . . . $$ \| 6 1 O O O X X . . . . . . $$ \| . 4 X X X O . . . . . . . $$ \| . . X O O O . O . . . . . $$ \| . . X X O . . . . . . . . $$ \| . . . . . . . . . . . . . $$ --------------------------[/go]`

Author: lightvector [ Sun Sep 11, 2011 12:51 pm ]

Post subject: Re: Tesuji Problem

Shaddy wrote:

Click Here To Show Diagram Code: [go]$$Bcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | 7 3 X . . . . . . . . . . $$ | 5 2 O . X . . . . . . . . $$ | 6 1 O O O X X . . . . . . $$ | . 4 X X X O . . . . . . . $$ | . . X O O O . O . . . . . $$ | . . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

But it's still ko if white descends?

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | 8 X X 2 . . . . . . . . . $$ | 1 O O . X . . . . . . . . $$ | 5 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | 6 4 X O O O . O . . . . . $$ | 9 . X X O . . . . . . . . $$ | . . . 7 . . . . . . . . . $$ --------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . 9 . O . . . . . . . . $$ | 6 X X 7 8 . . . . . . . . $$ | 1 O O 2 X . . . . . . . . $$ | 5 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | . 4 X O O O . O . . . . . $$ | . . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

Author: Solomon [ Sun Sep 11, 2011 1:19 pm ]

Post subject: Re: Tesuji Problem

lightvector wrote:

Shaddy wrote:

Click Here To Show Diagram Code: [go]$$Bcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | 7 3 X . . . . . . . . . . $$ | 5 2 O . X . . . . . . . . $$ | 6 1 O O O X X . . . . . . $$ | . 4 X X X O . . . . . . . $$ | . . X O O O . O . . . . . $$ | . . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

But it's still ko if white descends?

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | 8 X X 2 . . . . . . . . . $$ | 1 O O . X . . . . . . . . $$ | 5 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | 6 4 X O O O . O . . . . . $$ | 9 . X X O . . . . . . . . $$ | . . . 7 . . . . . . . . . $$ --------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . 9 . O . . . . . . . . $$ | 6 X X 7 8 . . . . . . . . $$ | 1 O O 2 X . . . . . . . . $$ | 5 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | . 4 X O O O . O . . . . . $$ | . . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | . X X 2 . . . . . . . . . $$ | 1 O O . X . . . . . . . . $$ | 5 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | 4 . X O O O . O . . . . . $$ | 6 . X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm1 10 at 5 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | . X X 2 . . . . . . . . . $$ | 1 O O . X . . . . . . . . $$ | 7 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | 4 9 X O O O . O . . . . . $$ | 5 6 X X O . . . . . . . . $$ | 8 . . . . . . . . . . . . $$ --------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm1 $$ | . . . . . . . . . . . . . $$ | . . O O X O . . . . . . . $$ | . . . . O . . . . . . . . $$ | . X X 2 . . . . . . . . . $$ | 1 O O . X . . . . . . . . $$ | 7 X O O O X X . . . . . . $$ | . 3 X X X O . . . . . . . $$ | 4 5 X O O O . O . . . . . $$ | 8 6 X X O . . . . . . . . $$ | . . . . . . . . . . . . . $$ --------------------------[/go]

Author:	lightvector [ Sun Sep 11, 2011 2:07 pm ]
Post subject:	Re: Tesuji Problem
Araban wrote: Click Here To Show Diagram Code `[go]$$Wcm1 $$ \| . . . . . . . . . . . . . $$ \| . . O O X O . . . . . . . $$ \| . . . . O . . . . . . . . $$ \| . X X 2 . . . . . . . . . $$ \| 1 O O . X . . . . . . . . $$ \| 5 X O O O X X . . . . . . $$ \| . 3 X X X O . . . . . . . $$ \| 4 . X O O O . O . . . . . $$ \| 6 . X X O . . . . . . . . $$ \| . . . . . . . . . . . . . $$ --------------------------[/go]` Wow B6 is really neat. Thanks. I wonder why the book author didn't choose a simpler position to illustrate this tesuji. Or maybe this line of resistance was just overlooked.

Author:	cyclops [ Mon Sep 12, 2011 5:44 am ]
Post subject:	Re: Tesuji Problem
Click Here To Show Diagram Code `[go]$$Wc $$ \| . . . . . . . . . $$ \| . . . , . . . . . $$ \| . . O O X O . . . $$ \| . . . . O . . . . $$ \| . X X X . . . . . $$ \| O O O . X . . . . $$ \| O . O O O X X . . $$ \| . O X X X O . . . $$ \| X 2 X O O O . O . $$ \| X 1 X X O . . . . $$ \| . 3 . . . . . . . $$ +-------------------[/go]` where is the unconditional kill?

Author:	daal [ Mon Sep 12, 2011 7:08 am ]
Post subject:	Re: Tesuji Problem
cyclops wrote: Click Here To Show Diagram Code `[go]$$Wc $$ \| . . . . . . . . . $$ \| . . . , . . . . . $$ \| . . O O X O . . . $$ \| . . . . O . . . . $$ \| . X X X . . . . . $$ \| O O O . X . . . . $$ \| O . O O O X X . . $$ \| . O X X X O . . . $$ \| X 2 X O O O . O . $$ \| X 1 X X O . . . . $$ \| . 3 . . . . . . . $$ +-------------------[/go]` where is the unconditional kill? How about this? White can play at neither a nor b, but black can play at a anytime. Click Here To Show Diagram Code `[go]$$ $$ \| . . . . . . . . . $$ \| . . . , . . . . . $$ \| . . O O X O . . . $$ \| . . . . O . . . . $$ \| 5 X X X . . . . . $$ \| O O O 3 X . . . . $$ \| O . O O O X X . . $$ \| b O X X X O . . . $$ \| X X X O O O . O . $$ \| X O X X O . . . . $$ \| a O 4 1 2 . . . . $$ +-------------------[/go]`

Author:	cyclops [ Mon Sep 12, 2011 7:52 am ]
Post subject:	Re: Tesuji Problem
daal wrote: How about this? thx, Daal. Great!

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