If I have to buy ONLY 1 book...

Don't know what book to read next? Have a killer reading list for improving joseki knowledge? This is this place.
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Chew Terr
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Re: If I have to buy ONLY 1 book...

Post by Chew Terr »

kukula wrote:Wow, thanks for the help! But I still don't understand!

Why isn't A16 a second eye for the white group, so that white can live no matter what happens in the corner?

I didn't realize just how much of a beginner I am!

Thanks!


A16 is white's first and only eye. A seki is a situation where neither player can kill the other without getting to play more than once in a row. In your example, if either player plays A19 (which white can't, anyways), B18, or A16, they are in atari. Even though black is outnumbered in the area, his two stones have as many liberties as all of the white ones. There are three ways that this could be resolved. First, it could remain seki forever, scoring no points for either. Second, either player could play something like B18 as a ko threat, in which case one player would get to kill the other here. Lastly, if white managed to kill some of the outside stones, like B14, white would have enough liberties to kill the two internal black stones.

Essentially, an eye doesn't count as an eye if there are opposing stones inside that you can't kill.
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Re: If I have to buy ONLY 1 book...

Post by kukula »

Li Kao wrote:If white plays B18 trying to kill blacks two stones it is self atari.


Ah, not suicide, but self-atari. Wow. Now I see. That space at A16 would be the white group's only remaining liberty.

So a real eye is just one empty space, which prevents any such funny business by black.

I sure have a lot to learn!

Thanks!
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Re: If I have to buy ONLY 1 book...

Post by kukula »

Chew Terr wrote:Essentially, an eye doesn't count as an eye if there are opposing stones inside that you can't kill.


That's the key. This seki stuff is something I am just learning about. I didn't realize how "interesting" it can get!

Thanks so much for all the help!
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Re: If I have to buy ONLY 1 book...

Post by Harleqin »

kukula wrote:So a real eye is just one empty space, which prevents any such funny business by black.


Not exactly. In this case, the black group simply forms an eye in the corner (yes, it is an eye, because White cannot approach at B18!), and the white group forms an eye at A16. So, these are two groups with one eye each, facing off at B18.

It is important to understand that both groups are alive.
A good system naturally covers all corner cases without further effort.
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Re: If I have to buy ONLY 1 book...

Post by kokomi »

kukula wrote:
kukula wrote:I have been studying Shotwell's Go! More Than a Game a bit.
[...]
He shows a seki example on pg 74. After W2, surely white has two good eyes and is immortal??? I don't see how black can threaten!


Here is a picture (if I can get the tags right!)

Image

How can black attack white here or get any kind of seki?

Thanks!


cannot white cut ?
Click Here To Show Diagram Code
[go]$$B Corner
$$ ------------------
$$ | . X O X . . . . .
$$ | X . O X . . . . .
$$ | O O O X . . . . .
$$ | . O X . 5 . . . .
$$ | O O X . . . . . .
$$ | X X 2 4 . . . . .
$$ | . 6 3 . . . . . .
$$ | 8 7 . . . . . . .
$$ | . . . . . . . . .[/go]
长考出臭棋.
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Chew Terr
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Re: If I have to buy ONLY 1 book...

Post by Chew Terr »

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

I don't know if this is better, but the atari obviously is bad for black. He can't afford to prioritize one over the other.

More importantly, in this sort of corner problem, I think it is generally asssumed that the outside are stable and connected out. So we just assume that there are more stones on the board than we can see, and that those stones connect to nullify issues like that.
Someday I want to be strong enough to earn KGS[-].
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Re: If I have to buy ONLY 1 book...

Post by kukula »

kokomi wrote:cannot white cut ?


I'm sorry - this really reveals my incompetence! Shotwell's book did not have that gap in the black stones! I didn't think it mattered! Wow! No wonder I lose almost every game I play!

To test my understanding - I have created a similar pattern but out away from the edge. Is this also a seki? Whoever plays at L10 puts themselves into atari - correct?
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Re: If I have to buy ONLY 1 book...

Post by kukula »

Chew Terr wrote:I don't know if this is better


It risks a ladder?

Click Here To Show Diagram Code
[go]$$B Corner
$$ ------------------
$$ | . X O X . . . . .
$$ | X . O X . . . . .
$$ | O O O X . . . . .
$$ | . O X 4 . . . . .
$$ | O O X . . . . . .
$$ | X X 2 . . . . . .
$$ | . 3 . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]


Wow, that go tag is nifty!
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Re: If I have to buy ONLY 1 book...

Post by kukula »

kukula wrote:It risks a ladder?


Oh, never mind! I can't think more than one move ahead!
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Chew Terr
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Re: If I have to buy ONLY 1 book...

Post by Chew Terr »

kukula wrote:To test my understanding - I have created a similar pattern but out away from the edge. Is this also a seki? Whoever plays at L10 puts themselves into atari - correct?


Great job! You have a lot better understanding of seki than I did at your level. =D

As far as the ladder thing, yeah, there would be fighting and such. I didn't even bother reading if there was a way to live for sure. Like I said, often corner problems will have unclear boundaries that we just have to take for granted, so I assumed it was just meant that way.
Someday I want to be strong enough to earn KGS[-].
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Re: If I have to buy ONLY 1 book...

Post by prokofiev »

kukula wrote:
Chew Terr wrote:I don't know if this is better


It risks a ladder?

Click Here To Show Diagram Code
[go]$$B Corner
$$ ------------------
$$ | . X O X . . . . .
$$ | X . O X . . . . .
$$ | O O O X . . . . .
$$ | . O X 4 . . . . .
$$ | O O X . . . . . .
$$ | X X 2 . . . . . .
$$ | . 3 . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]


Wow, that go tag is nifty!


This is a good idea actually:

Click Here To Show Diagram Code
[go]$$B Corner
$$ ------------------
$$ | . X O X . . . . .
$$ | X . O X . . . . .
$$ | O O O X 7 . . . .
$$ | . O X 4 6 . . . .
$$ | O O X 5 8 . . . .
$$ | X X 2 9 . . . . .
$$ | . 3 0 . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .[/go]


Click Here To Show Diagram Code
[go]$$Bm11 Corner
$$ ------------------
$$ | . X O X . . . . .
$$ | X . O X . . . . .
$$ | O O O X X . . . .
$$ | . O X O O . . . .
$$ | O O X X O . . . .
$$ | X X O X . . . . .
$$ | . X O 2 . . . . .
$$ | . 1 . . . . . . .
$$ | . . . . . . . . .[/go]


Ladder!
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kokomi
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Re: If I have to buy ONLY 1 book...

Post by kokomi »

prokofiev wrote:
Click Here To Show Diagram Code
[go]$$Bm11 Corner
$$ ------------------
$$ | . X O X . . . . .
$$ | X . O X . . . . .
$$ | O O O X X . . . .
$$ | . O X O O . . . .
$$ | O O X X O . . . .
$$ | X X O X . . . . .
$$ | . X O 2 . . . . .
$$ | . 1 . . . . . . .
$$ | . . . . . . . . .[/go]


Ladder!


How did you get 11 and 12? I look at the code, it's still 1 and 2.
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Li Kao
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Re: If I have to buy ONLY 1 book...

Post by Li Kao »

It has $$Bm11 in the header. m11 says it starts with move 11. Check the diagram manual.
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Re: If I have to buy ONLY 1 book...

Post by Harleqin »

kukula wrote:To test my understanding - I have created a similar pattern but out away from the edge. Is this also a seki? Whoever plays at L10 puts themselves into atari - correct?


Yes.
A good system naturally covers all corner cases without further effort.
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Re: If I have to buy ONLY 1 book...

Post by kokomi »

Li Kao wrote:It has $$Bm11 in the header. m11 says it starts with move 11. Check the diagram manual.


Ha, thanks.

How about this, kukula :roll:
Click Here To Show Diagram Code
[go]$$
$$ ------------------
$$ . . O O X X O O .
$$ . . O X . . X O .
$$ . . O X . . X O .
$$ . . O X O O X O .
$$ . . O X X X X O .
$$ . . O O O O O O .
$$ . . . . . . . . .
$$ . . . . . . . . .
$$ . . . . . . . . .[/go]
长考出臭棋.
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