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Problem I ran into in a game

https://lifein19x19.com/viewtopic.php?t=8681

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Problem I ran into in a game

Posted: Mon Jul 08, 2013 10:23 pm
by NoSkill
I was white in a handicap game and this was the board:



Try to find a black move that looks like it works, but really doesn't.

Hint:
trying for seki



Okay so if black had played that, try to guess why it doesn't work (the real problem)



Hint:
No ko, no seki, no trade offs












Could be wrong as this is just something that came up and not like something I studied, other than in game :P

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:01 pm
by moyoaji
Why doesn't this work?

So this is the basic shape you are talking about? As far as I can tell white doesn't have any tricks to prevent black from getting this kind of shape as any internal moves would allow black to live outright when he captures white and white doesn't have a way to kill any part of black's wall before white dies himself.
Click Here To Show Diagram Code
[go]$$
$$ | . . . . . .
$$ | O O O O O .
$$ | X X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | X X X O . .
$$ | O O O O . .
$$ | . . . . . .[/go]

This looks like seki to me if black gets the first move into any of the inside spots, which black has the liberties on the outside to do in your problem. What am I missing?

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:31 pm
by Unusedname
moyoaji wrote:Why doesn't this work?

So this is the basic shape you are talking about? As far as I can tell white doesn't have any tricks to prevent black from getting this kind of shape as any internal moves would allow black to live outright when he captures white and white doesn't have a way to kill any part of black's wall before white dies himself.
Click Here To Show Diagram Code
[go]$$
$$ | . . . . . .
$$ | O O O O O .
$$ | X X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | X X X O . .
$$ | O O O O . .
$$ | . . . . . .[/go]

This looks like seki to me if black gets the first move into any of the inside spots, which black has the liberties on the outside to do in your problem. What am I missing?



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


black doesn't have these stones.

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

he has these ones.

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:38 pm
by moyoaji
Unusedname wrote:
Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | B O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | . X X O . .
$$ | B O O O . .
$$ | . O . . . .[/go]

he has these ones.

My point was that black can create this shape without being interrupted by white. White cannot stop black from filling those side tiger's mouths. Black has too many outside liberties. I was just trying to simplify things. If there is a mistake I'm making in reading out how white can play this situation then let me know, that's what I want to find out because apparently the simple answer that I gave is incorrect.

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:42 pm
by Kirby
moyoaji wrote:
Unusedname wrote:
Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | B O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | . X X O . .
$$ | B O O O . .
$$ | . O . . . .[/go]

he has these ones.

My point was that black can create this shape without being interrupted by white. White cannot stop black from filling those side tiger's mouths. Black has too many outside liberties. I was just trying to simplify things. If there is a mistake I'm making in reading out how white can play this situation then let me know, that's what I want to find out because apparently the simple answer that I gave is incorrect.


White just has to throw in and the shape is different:
Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | X O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | W X X O . .
$$ | X O O O . .
$$ | . O . . . .[/go]

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:44 pm
by moyoaji
Kirby wrote:
White just has to throw in and the shape is different:
Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | X O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | W X X O . .
$$ | X O O O . .
$$ | . O . . . .[/go]

Look at the original post. The black stones are not surrounded. They have outside liberties. White cannot play like this.

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:46 pm
by Kirby
moyoaji wrote:
Kirby wrote:
White just has to throw in and the shape is different:
Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | X O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | W X X O . .
$$ | X O O O . .
$$ | . O . . . .[/go]

Look at the original post. The black stones are not surrounded. They have outside liberties. White cannot play like this.


Why can't white play like this? It's white's turn. He doesn't have to fill outside liberties. He can play the throw-in immediately.

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:50 pm
by Unusedname
moyoaji wrote:
Kirby wrote:
White just has to throw in and the shape is different:
Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | X O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | W X X O . .
$$ | X O O O . .
$$ | . O . . . .[/go]

Look at the original post. The black stones are not surrounded. They have outside liberties. White cannot play like this.



I missed the throw in too at first.
But I can't think of any other black moves.


edit:
actually there is a throw in continuation black can do but it still leads to a dead shape.

Re: Problem I ran into in a game

Posted: Mon Jul 08, 2013 11:56 pm
by moyoaji
Kirby wrote:
Why can't white play like this? It's white's turn. He doesn't have to fill outside liberties. He can play the throw-in immediately.

Now I see it. It is the double throw-in that black needs to worry about. After a couple of moves white throws in to the other tigers mouth and then the shape is reduced to a dead shape on the inside. I didn't consider what would happen if both were played.

Re: Problem I ran into in a game

Posted: Tue Jul 09, 2013 8:31 am
by Shaddy
moyoaji wrote:Why doesn't this work?

So this is the basic shape you are talking about? As far as I can tell white doesn't have any tricks to prevent black from getting this kind of shape as any internal moves would allow black to live outright when he captures white and white doesn't have a way to kill any part of black's wall before white dies himself.
Click Here To Show Diagram Code
[go]$$
$$ | . . . . . .
$$ | O O O O O .
$$ | X X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | X X X O . .
$$ | O O O O . .
$$ | . . . . . .[/go]

This looks like seki to me if black gets the first move into any of the inside spots, which black has the liberties on the outside to do in your problem. What am I missing?


Piling on the train,

that is not a seki. White kills.

Re: Problem I ran into in a game

Posted: Tue Jul 09, 2013 8:58 am
by Bill Spight
Shaddy wrote:
moyoaji wrote:Why doesn't this work?

So this is the basic shape you are talking about? As far as I can tell white doesn't have any tricks to prevent black from getting this kind of shape as any internal moves would allow black to live outright when he captures white and white doesn't have a way to kill any part of black's wall before white dies himself.
Click Here To Show Diagram Code
[go]$$
$$ | . . . . . .
$$ | O O O O O .
$$ | X X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | X X X O . .
$$ | O O O O . .
$$ | . . . . . .[/go]

This looks like seki to me if black gets the first move into any of the inside spots, which black has the liberties on the outside to do in your problem. What am I missing?


Piling on the train,

that is not a seki. White kills.


Click Here To Show Diagram Code
[go]$$
$$ | . . . . . . .
$$ | O O O O O . .
$$ | X X X X O . .
$$ | . O . X O . .
$$ | X O X X X O .
$$ | . O X O . O .
$$ | X X X O . . .
$$ | O O O O . O .
$$ | . . . . . . .[/go]


OK, fixed. ;)

Re: Problem I ran into in a game

Posted: Tue Jul 09, 2013 9:03 am
by NoSkill
Kirby got it ^^.

Its hard to see :D

Re: Problem I ran into in a game

Posted: Tue Jul 09, 2013 3:52 pm
by NoSkill
Oh also, outside liberties didn't matter at all.

And you only need one white stone, not two. Try looking at it again moyoaji, and see if you notice the difference :D.

Re: Problem I ran into in a game

Posted: Tue Jul 09, 2013 4:32 pm
by leichtloeslich
Shaddy wrote:that is not a seki. White kills.

To his defense, he didn't say it was a seki, he said it'd become a seki if black gets any of the inside moves, which is correct.

@moyoaji:

Do you see the difference in these positions?
Click Here To Show Diagram Code
[go]$$
$$ ------------------
$$ | . X . . X . . . .
$$ | X X X X O O O . .
$$ | O O O O O . . . .
$$ | . . . . . . . . .[/go]


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


It's not about there being a connection, but about eyespace.

Re: Problem I ran into in a game

Posted: Tue Jul 09, 2013 6:03 pm
by Splatted
NoSkill wrote:Oh also, outside liberties didn't matter at all.

And you only need one white stone, not two. Try looking at it again moyoaji, and see if you notice the difference :D.


I'm confused by this. Why doesn't white need to play both throw-ins?

Click Here To Show Diagram Code
[go]$$
$$ | . O . . . .
$$ | X O O O O .
$$ | . X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | . O X O O .
$$ | W X X O . .
$$ | X O O O . .
$$ | . O . . . .[/go]


Eventually results in:

Click Here To Show Diagram Code
[go]$$
$$ | O O . . . .
$$ | X O O O O .
$$ | X X X X O .
$$ | . O . X O .
$$ | X O X X O .
$$ | X O X O O .
$$ | X X X O . .
$$ | X O O O . .
$$ | O O . . . .[/go]


Which is seki, and other than the second throw in the only sensible looking move for white is:

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


But he loses the capturing race.

Edit: And don't tell me that :w4: should be at "a", because that's just playing the throw-in.
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