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Fun tsumego problem
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Author:  dfan [ Wed Jun 30, 2010 7:23 am ]
Post subject:  Fun tsumego problem
From Takeo Shinji's Strongest Tsumego for Shodan, Mid Kyu and Low Kyu (link to tchan's godiscussions' post) amazon.co.jp link

I made an amazon.co.jp order a few months back to get the Maeda set and threw in a bunch of these pocket-sized books. They're great.

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

Put your answer in hide tags, of course!
Author:  Chew Terr [ Wed Jun 30, 2010 7:26 am ]
Post subject:  Re: Fun tsumego problem
Click Here To Show Diagram Code
[go]$$Bc Clean kill?
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . . X 3 . 2 |
$$ -----------------[/go]

Click Here To Show Diagram Code
[go]$$Bc Alternate block fails?
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . 3 X . 2 . |
$$ -----------------[/go]


Edit: changed attempt. Thanks for the hint, Bill!
Author:  Bill Spight [ Wed Jun 30, 2010 7:28 am ]
Post subject:  Re: Fun tsumego problem
Hint.

The opponent's move is not my move.

(Not much of a hint, I know. Here's another.)

A shortage of liberties is worse than constipation. (That's a pun in Japanese.)
Author:  Redundant [ Wed Jun 30, 2010 7:31 am ]
Post subject:  Re: Fun tsumego problem
Fun!

Click Here To Show Diagram Code
[go]$$c Black to play
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . . X 3 . 2 |
$$ -----------------[/go]
Author:  tchan001 [ Wed Jun 30, 2010 7:34 am ]
Post subject:  Re: Fun tsumego problem
Click Here To Show Diagram Code
[go]$$Bc
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . . X 3 . 2 |
$$ -----------------[/go]

No, I didn't look it up. I thought it out
Author:  daniel_the_smith [ Wed Jun 30, 2010 7:39 am ]
Post subject:  Re: Fun tsumego problem
That one seemed impossible the first time I saw it, I'll never forget it...
Author:  fwiffo [ Wed Jun 30, 2010 7:54 am ]
Post subject:  Re: Fun tsumego problem
Click Here To Show Diagram Code
[go]$$B Shortage of liberties
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . . X 3 . 2 |
$$ -----------------[/go]

I think this works.

Reminds me of this classic:
Author:  deja [ Wed Jun 30, 2010 8:09 am ]
Post subject:  Re: Fun tsumego problem
Wouldn't this work as well?

Click Here To Show Diagram Code
[go]$$B Shortage of liberties
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O . |
$$ . . . . . X . 1 . |
$$ -----------------[/go]
Author:  daniel_the_smith [ Wed Jun 30, 2010 8:10 am ]
Post subject:  Re: Fun tsumego problem
@deja
That's ko.
Click Here To Show Diagram Code
[go]$$B ko
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O . |
$$ . . . . . X . 1 2 |
$$ -----------------[/go]
Author:  deja [ Wed Jun 30, 2010 8:14 am ]
Post subject:  Re: Fun tsumego problem
Click Here To Show Diagram Code
[go]$$B Shortage of liberties
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 3 |
$$ . . . . . X . 1 2 |
$$ -----------------[/go]


Am I missing something? I'm sure I am...
Author:  daniel_the_smith [ Wed Jun 30, 2010 8:16 am ]
Post subject:  Re: Fun tsumego problem
Right, so white makes a ko threat...
Author:  deja [ Wed Jun 30, 2010 8:23 am ]
Post subject:  Re: Fun tsumego problem
daniel_the_smith wrote:
Right, so white makes a ko threat...


But wherever white moves next, black just takes that group, no?
Author:  daniel_the_smith [ Wed Jun 30, 2010 8:29 am ]
Post subject:  Re: Fun tsumego problem
Well, that would depend on the size of the threat and the rest of the board :)

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



Click Here To Show Diagram Code
[go]$$B ko
$$ 4 5 . . . . . . . |
$$ 7 8 . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O X |
$$ . . . . . X a X 6 |
$$ -----------------[/go]


Instead of :b5:, black could capture at (a) to win the ko. Instead of :w8:, white can capture at (a) to win the ko.
Author:  averell [ Wed Jun 30, 2010 9:12 am ]
Post subject:  Re: Fun tsumego problem
Chew Terr wrote:
Click Here To Show Diagram Code
[go]$$Bc Clean kill?
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . . X 3 . 2 |
$$ -----------------[/go]

Click Here To Show Diagram Code
[go]$$Bc Alternate block fails?
$$ . . . . . . . . . |
$$ . . . . . . . . . |
$$ . . . . . X X X X |
$$ . . X X X O O O O |
$$ . . X O O X O O 1 |
$$ . . . . 3 X . 2 . |
$$ -----------------[/go]


Edit: changed attempt. Thanks for the hint, Bill!

correct, but since nobody said it, in your alternate case it's one point better to pass for move 3 :)
Author:  Nakamura [ Wed Jun 30, 2010 9:43 am ]
Post subject:  Re: Fun tsumego problem
Reminds me of the Golden Chicken Standing on One Leg. ^_^


Best named tesuji ever.



Cool problem, but I solved it. So it must be really easy. I never get hard ones. o.o
Author:  dfan [ Wed Jun 30, 2010 11:11 am ]
Post subject:  Re: Fun tsumego problem
deja wrote:
daniel_the_smith wrote:
Right, so white makes a ko threat...

But wherever white moves next, black just takes that group, no?

What if white's next move threatens to capture 40 stones? Do you still just take the lower right group?

Here's a more quantitative way to look at it than just "killing is better than ko":

In your solution, the sequence goes bwbWbW, where uppercase letters are moves played elsewhere on the board.
In the correct solution, the sequence goes bwbW (or bW, if White stops thrashing).

In both cases, both players have played the same number of moves as each other. But in your solution, white has gotten to play an extra stone somewhere else on the board for free (two capital W's instead of one).
Author:  deja [ Wed Jun 30, 2010 12:48 pm ]
Post subject:  Re: Fun tsumego problem
dfan wrote:
deja wrote:
daniel_the_smith wrote:
Right, so white makes a ko threat...

But wherever white moves next, black just takes that group, no?

What if white's next move threatens to capture 40 stones? Do you still just take the lower right group?

Here's a more quantitative way to look at it than just "killing is better than ko":

In your solution, the sequence goes bwbWbW, where uppercase letters are moves played elsewhere on the board.
In the correct solution, the sequence goes bwbW (or bW, if White stops thrashing).

In both cases, both players have played the same number of moves as each other. But in your solution, white has gotten to play an extra stone somewhere else on the board for free (two capital W's instead of one).


I was looking at the problem from a local position only, since we have no idea what else is on the board. So "wherever white moves next" was in the context of white trying to save the two groups.
Author:  Solomon [ Wed Jun 30, 2010 12:50 pm ]
Post subject:  Re: Fun tsumego problem
When you see and solve this problem the first time, it really is hard to forget it because the solution, while not particularly difficult, is just so cute.
Author:  SoDesuNe [ Wed Jun 30, 2010 12:58 pm ]
Post subject:  Re: Fun tsumego problem
Yeah, I also had a hard time with this problem in "Graded Go Problems For Beginners Volume 3". There were like a handful with this tactic. Pretty astonishing =)
Author:  k43r [ Wed Jun 30, 2010 2:09 pm ]
Post subject:  Re: Fun tsumego problem
Image

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Similar problem, but from real kgs game. B to kill ^^ (solution wasn't played in game, kibitz found it)
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