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Life & Death from a game
http://www.lifein19x19.com/viewtopic.php?f=15&t=4619		 Page 1 of 1
Author:  judicata [ Wed Sep 07, 2011 6:27 pm ]
Post subject:  Life & Death from a game
Here is a life and death problem from a recent game, white to kill (on the right side, obviously):

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$c White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . X O O . . .|
$$ |. X X X O . O . O X . X O X X O O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]
Author:  Koosh [ Wed Sep 07, 2011 8:10 pm ]
Post subject:  Re: Life & Death from a game
Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$c White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . X O O . . .|
$$ |. X X X O . O . O X W X O X X O O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]


:mrgreen:
Author:  daniel_the_smith [ Wed Sep 07, 2011 8:22 pm ]
Post subject:  Re: Life & Death from a game
Koosh got it, of course.

But I wanted this to be the solution:

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$c White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . X O O . . .|
$$ |. X X X O . O . O X . X O X X O O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . W X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]


So I was about to post this modified position:

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$c White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . X O O . . .|
$$ |. X X X O . O O . X . X O X X O O . .|
$$ |X . X . X O . . O O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]


Unfortunately, while Koosh's answer doesn't kill this one, neither does mine, because black has a surprising (to me) response. :(
Author:  jts [ Wed Sep 07, 2011 8:33 pm ]
Post subject:  Re: Life & Death from a game
@daniel
It looks to me like L19 and L17 both work... is there a problem with one of them?
Author:  tchan001 [ Wed Sep 07, 2011 8:34 pm ]
Post subject:  Re: Life & Death from a game
Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$c White to kill
$$ ---------------------------------------
$$ |. . . O . . . . W X . O . X O O . . .|
$$ |. X X X O . O . O X . X O X X O O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]
Author:  daniel_the_smith [ Wed Sep 07, 2011 8:38 pm ]
Post subject:  Re: Life & Death from a game
@jts

I was thinking of L19, but yeah, both work. Time for bed!
Author:  Koosh [ Wed Sep 07, 2011 8:52 pm ]
Post subject:  Re: Life & Death from a game
GrawWw, daniel's answer to the original problem is better than mine :blackeye:
Author:  Solomon [ Wed Sep 07, 2011 9:30 pm ]
Post subject:  Re: Life & Death from a game
A small tweak:
Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . . X O O . .|
$$ |. X X X O . O . O X . X O . . X O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]
Author:  judicata [ Thu Sep 08, 2011 10:18 am ]
Post subject:  Re: Life & Death from a game
Koosh was cheating, as he watched the game in which this arose. I played his proposed solution--but I didn't realize there was more than one answer...
Author:  Shaddy [ Thu Sep 08, 2011 12:31 pm ]
Post subject:  Re: Life & Death from a game
Araban wrote:
A small tweak:
Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . . X O O . .|
$$ |. X X X O . O . O X . X O . . X O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]


Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X 6 O 2 5 X O O . .|
$$ |. X X X O . O . O X 3 X O 1 7 X O . .|
$$ |X . X . X O . . . O 4 X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]
Author:  lightvector [ Thu Sep 08, 2011 5:51 pm ]
Post subject:  Re: Life & Death from a game
Shaddy wrote:
Araban wrote:
A small tweak:
Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O . . X O O . .|
$$ |. X X X O . O . O X . X O . . X O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]


Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X 6 O 2 5 X O O . .|
$$ |. X X X O . O . O X 3 X O 1 7 X O . .|
$$ |X . X . X O . . . O 4 X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]


How does white respond to this?

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X 2 O . . X O O . .|
$$ |. X X X O . O . O X . X O 1 . X O . .|
$$ |X . X . X O . . . O . X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]
Author:  EricBackus [ Thu Sep 08, 2011 7:35 pm ]
Post subject:  Re: Life & Death from a game
Back to the original problem for a moment...

My first thought was to reduce the eyespace by playing at L17.

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O 3 X O O . . .|
$$ |. X X X O . O . O X 2 X O X X O O . .|
$$ |X . X . X O . . . O 1 X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X 2 O . X O O . . .|
$$ |. X X X O . O . O X 3 X O X X O O . .|
$$ |X . X . X O . . . O 1 X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]

Go Diagram
White to kill
Click Here To Show Diagram Code
[go]$$Wc White to kill
$$ ---------------------------------------
$$ |. . . O . . . . . X . O 2 X O O . . .|
$$ |. X X X O . O . O X 3 X O X X O O . .|
$$ |X . X . X O . . . O 1 X X X X X O . .|
$$ |. X . , X X O . . O O X X O O X O . .|
$$ |. O X . X X . . . . . X O . O O X O .|
$$ |. . O X . X . . . O . O . O . . X . .|
$$ |. X . O X O O . . . . . . . . . X . .|[/go]

If reducing the eyespace works, why look for more complicated scenarios?
Author:  judicata [ Thu Sep 08, 2011 11:20 pm ]
Post subject:  Re: Life & Death from a game
EricBackus wrote:
If reducing the eyespace works, why look for more complicated scenarios?


Because more complicated=cooler. :batman:
Author:  EricBackus [ Fri Sep 09, 2011 9:09 am ]
Post subject:  Re: Life & Death from a game
judicata wrote:
EricBackus wrote:
If reducing the eyespace works, why look for more complicated scenarios?

Because more complicated=cooler. :batman:

OK, true. :cool:
Author:  Joaz Banbeck [ Fri Sep 09, 2011 12:52 pm ]
Post subject:  Re: Life & Death from a game
Less complicated = more elegant.
Author:  judicata [ Fri Sep 09, 2011 5:50 pm ]
Post subject:  Re: Life & Death from a game
Joaz Banbeck wrote:
Less complicated = more elegant.


BAH! :)
Author:  Shaddy [ Sun Sep 11, 2011 12:34 pm ]
Post subject:  Re: Life & Death from a game
If two solutions both kill/live, start counting ko threats and endgame points.
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