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4 LD's from 1001 L&D problems

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4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 11:05 am
by cyclops
Black to move: Find the first 5 moves of the main-variant that kills W unconditionally or in double ko. If there are more solutions find the most profitable or most simple one. I publish the ( book ) solutions after 10 days. Difficulty: sdk

Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . . O . . . . . X O X O |
$$ | O O . . . X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . . . |
$$ | . . . . O X . . X X O . . |
$$ +---------------------------+[/go]


I'm interested in how you estimate the difficulty of each problem. So I look forward to reactions like:
b > a = d > c ( c is easiest ) or
b = 500 s, a = d = 100 s, d = 40 s. ( for this 7 kyu, s for seconds ) or
b = 4 k, a = d = 6k, d = 8k.

I recommend the book "One thousand and one Life-and-Death problems" by Richard Bozulich, Kiseido Publishing Company.

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 11:35 am
by Mnemonic
Because I'm only a 10k I only looked at the easiest problem and after some time I think I found the solution.
It took me about 90 seconds and I'm pretty certain I wouldn't have seen it in a real game :-?
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . 5 1 O . . . . . X O X O |
$$ | O O 2 4 3 X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . . . |
$$ | . . . . O X . . X X O . . |
$$ +---------------------------+[/go]

I am probably closer to 9k than 10k and I found this problem challenging but doable so the estimate of 8k sounds reasonable

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 11:59 am
by jts
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . 4 1 O . . . . . X O X O |
$$ | O O 2 5 3 X . . . X O 3 5 |
$$ | O X O O O X . . . X O 4 X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O 2 |
$$ | . . . . . . . . . . X O 1 |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X 3 O O . |
$$ | O 2 O . O X . . X O . 2 1 |
$$ | . 1 3 . O X . . X X O . . |
$$ +---------------------------+[/go]


Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . 1 O . . . . . X O X O |
$$ | O O 3 . 2 X . . . X O 2 . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O 3 |
$$ | . . . . . . . . . . X O 1 |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . 5 O X X . . X 2 O O . |
$$ | O . O 3 O X . . X O . 3 1 |
$$ | . 1 2 4 O X . . X X O . . |
$$ +---------------------------+[/go]


d= 1min, c= 1min (but then when doing the diagram I forgot the main line and spent 10 minutes trying to find a different solution...), b= 3 min, a=5 min

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 3:02 pm
by Dusk Eagle
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . 1 O . . . . . X O X O |
$$ | O O 3 . 2 X . . . X O 3 . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . . . . . . X O O 2 |
$$ | . . . . . . . . . . X O 1 |
$$ | . . . , . . , . . , X X X |
$$ | . 7 . . . . . . . . . . . |
$$ | . 6 X X . . . . . . X X X |
$$ | 8 X O X . . , . X , X O O |
$$ | . 2 4 O X X . . X 3 O O . |
$$ | O 9 O 3 O X . . X O . 2 1 |
$$ | . 5 1 . O X . . X X O . . |
$$ +---------------------------+[/go]

Assuming I got them all right, I think they're all around equal difficulty, about the range for me where it's pretty quick to solve them as problems but I might take a bit during the game, depending on how I was feeling. I suppose the bottom-left was the hardest, as I tried the most points before finding the right (?) one and white can resist a bit stronger than in the other corners.

Edit: Derp, I read out :w2: at :b5: in the lower left, but somehow misevaluated it. That was stupid of me.

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 3:12 pm
by Sverre
cyclops wrote:Black to move: Find the first 5 moves of the main-variant that kills W unconditionally or in double ko. If there are more solutions find the most profitable or most simple one. I publish the ( book ) solutions after 10 days. Difficulty: sdk

Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . 2 1 O 5 . . . . X O X O |
$$ | O O . 3 4 X . . . X O 4 3 |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . 2 |
$$ | . . . . d . . . c X O O 5 |
$$ | . . . . . . . . . . X O 1 |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . 1 . O X X . . X 3 O O . |
$$ | O 2 O 5 O X . . X O 5 2 1 |
$$ | . 3 4 . O X . . X X O . 4 |
$$ +---------------------------+[/go]


c > a > d > b


@Dusk Eagle:
Click Here To Show Diagram Code
[go]$$
$$ | . . . . . . .
$$ | . . X X . . .
$$ | . X O X . . ,
$$ | . . . O X X .
$$ | O . O . O X .
$$ | . 2 1 . O X .
$$ +--------------[/go]


@jts
Click Here To Show Diagram Code
[go]$$ Do you have a plan to refute this W 2?
$$ | . . . . . . .
$$ | . . X X a . .
$$ | . X O X . . ,
$$ | . 2 . O X X .
$$ | O . O . O X .
$$ | . 1 . . O X .
$$ +--------------[/go]

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 4:02 pm
by jts
@sverre: didn't see that! :roll:

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 4:21 pm
by hyperpape
I was going to say
d<a< b < c
where spacing denotes how close they are in difficulty.

However, I uh...got d wrong :oops: . I got a and b right, at least if sverre is right. I could not solve c. I think the double ko bit was something of a hint.

I'm really awful at tsumego.

Re: 4 LD's from 1001 L&D problems

Posted: Thu Feb 17, 2011 7:08 pm
by cyclops
If you want to see the solutions: check Sverre. But they are not the only correct ones.

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 3:25 am
by daal
My initial impression was:

b is the easiest, then d, then c then a.

b looks like a one move problem, and after :b1: I can't see a move for w:
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . . O . . . . . X O X O |
$$ | O O . . . X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . 1 . |
$$ | . . . . O X . . X X O . . |
$$ +---------------------------+[/go]


d looks easy, because there don't seem to be many possibilities. However it is a shortage of liberties problem, and I would have missed my solution in a game. both :b1: and :b3: are forcing moves and after :b5: w can't connect:

Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . 2 1 M 5 . . . . X O X O |
$$ | O O . 3 4 X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . . . |
$$ | . . . . O X . . X X O . . |
$$ +---------------------------+[/go]


c looked harder, but when I tried it, it was pretty easy. After seeing that the obvious move at m12 fails, I tried the hane at :b1: At first I though w could get a ko with :w2: and :w4: , but :b5: does away with that hope:

Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . . O . . . . . X O X M |
$$ | O O . . . X . . . X O . 5 |
$$ | O X O O O X . . . X O 4 X |
$$ | X X X X X X , . . X O . 2 |
$$ | . . . . d . . . c X O O 3 |
$$ | . . . . . . . . . . X O 1 |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . . . |
$$ | . . . . O X . . X X O . . |
$$ +---------------------------+[/go]


a looked difficult because kos seem to pop up everywhere, and although "a" looks like it can do something evil, I couldn't find a solution without ko.
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . . O . . . . . X O X O |
$$ | O O . . . X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . . . |
$$ | . . a . O X . . X X O . . |
$$ +---------------------------+[/go]


So, after trying b is easier than c which is easier than d which is easier than a.

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 3:33 am
by topazg
daal wrote:
My initial impression was:

b is the easiest, then d, then c then a.

b looks like a one move problem, and after :b1: I can't see a move for w:
Click Here To Show Diagram Code
[go]$$c
$$ +---------------------------+
$$ | . . . O . . . . . X O X O |
$$ | O O . . . X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O . 1 . |
$$ | . . . . O X . . X X O . . |
$$ +---------------------------+[/go]


Click Here To Show Diagram Code
[go]$$c "a" and "b" miai for White life?
$$ +---------------------------+
$$ | . . . O . . . . . X O X O |
$$ | O O . . . X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O b 1 2 |
$$ | . . . . O X . . X X O a . |
$$ +---------------------------+[/go]

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 3:51 am
by topazg
Sverre wrote:
@jts
Click Here To Show Diagram Code
[go]$$ Do you have a plan to refute this W 2?
$$ | . . . . . . .
$$ | . . X X a . .
$$ | . X O X . . ,
$$ | . 2 . O X X .
$$ | O . O . O X .
$$ | . 1 . . O X .
$$ +--------------[/go]


Click Here To Show Diagram Code
[go]$$ :w6: goes running, but the corner dies
$$ | . 6 . . . . .
$$ | . 4 X X a . .
$$ | 5 X O X . . ,
$$ | . 2 8 O X X .
$$ | O 9 O 7 O X .
$$ | . 1 3 . O X .
$$ +--------------[/go]


Click Here To Show Diagram Code
[go]$$ It all dies
$$ | . 7 . . . . .
$$ | 6 4 X X a . .
$$ | 5 X O X . . ,
$$ | 8 2 . O X X .
$$ | O . O 9 O X .
$$ | . 1 3 . O X .
$$ +--------------[/go]


Click Here To Show Diagram Code
[go]$$ It dies here too
$$ | . . . . . . .
$$ | . 5 X X a . .
$$ | . X O X . . ,
$$ | . 2 . O X X .
$$ | O . O 4 O X .
$$ | . 1 3 . O X .
$$ +--------------[/go]


Does this work?

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 4:06 am
by Sverre
topazg wrote:
Click Here To Show Diagram Code
[go]$$ :w6: goes running, but the corner dies
$$ | . 6 . . . . .
$$ | . 4 X X a . .
$$ | 5 X O X . . ,
$$ | . 2 8 O X X .
$$ | O 9 O 7 O X .
$$ | . 1 3 . O X .
$$ +--------------[/go]


Does this work?


Yes, that seems to work. I hadn't read the continuation out beyond :b2: thoroughly.

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 4:54 am
by cyclops
Sverre wrote:
topazg wrote:
Click Here To Show Diagram Code
[go]$$ :w6: goes running, but the corner dies
$$ | . 6 . . . . .
$$ | . 4 X X a . .
$$ | 5 X O X . . ,
$$ | . 2 8 O X X .
$$ | O 9 O 7 O X .
$$ | . 1 3 . O X .
$$ +--------------[/go]


Does this work?


Yes, that seems to work. I hadn't read the continuation out beyond :b2: thoroughly.


I usually come up with the most complicated solution, so I have
In Topasz' last diagram: 3 @ 7. Does this work?

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 4:55 am
by daal
topazg wrote:
Click Here To Show Diagram Code
[go]$$c "a" and "b" miai for White life?
$$ +---------------------------+
$$ | . . . O . . . . . X O X O |
$$ | O O . . . X . . . X O . . |
$$ | O X O O O X . . . X O . X |
$$ | X X X X X X , . . X O . . |
$$ | . . . . d . . . c X O O . |
$$ | . . . . . . . . . . X O . |
$$ | . . . , . . , . . , X X X |
$$ | . . . . . . . . . . . . . |
$$ | . . X X a . . . b . X X X |
$$ | . X O X . . , . X , X O O |
$$ | . . . O X X . . X . O O . |
$$ | O . O . O X . . X O b 1 2 |
$$ | . . . . O X . . X X O a . |
$$ +---------------------------+[/go]


I didn't see that "b" was a self atari :-?

I can't find anything that doesn't end in ko :o

I guess I have to revise my list:

a hardest, b ???, d hard, c manageable.

Re: 4 LD's from 1001 L&D problems

Posted: Fri Feb 18, 2011 5:15 am
by topazg
daal wrote:
I didn't see that "b" was a self atari :-?

I can't find anything that doesn't end in ko :o

I guess I have to revise my list:

a hardest, b ???, d hard, c manageable.


Spoiler hint about "b":

It is ko ... twice ;)


Full Spoiler about "b":

Click Here To Show Diagram Code
[go]$$c If :w4: @ :b5:, then :b5: @ :w4: kills
$$ | . . . . . . . . . . . . . |
$$ | . . . . . . . . . . X X X |
$$ | . . . , . . , . X , X O O |
$$ | . . . . . . . . X 3 O O . |
$$ | . . . . . . . . X O 5 2 1 |
$$ | 6 . . . . . . . X X O . 4 |
$$ +---------------------------+[/go]


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


It's a double ko. It doesn't matter how many threats White creates, Black can just capture the other ko.
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