Capture race in Shotwell

If you're new to the game and have questions, post them here.
Post Reply
kukula
Dies in gote
Posts: 26
Joined: Thu Jul 29, 2010 5:26 am
Rank: KGS 22 kyu
GD Posts: 0
KGS: kukula
Location: USA: New York State
Contact:

Capture race in Shotwell

Post by kukula »

From Shotwell's Go! More Than a Game p. 109...

Here is a situation I just don't get:

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


The caption reads: "White dies". How so? That black chain with B3 and B5 - it's it atari, right? It is certain a race - that white chain with one eye has just one liberty beyond the eye. But what can black do?

Got to extend to T14 with B7, right? Then why not W8 at T15, so that black group is still in atari. Sure, B9 at T13 would put the big white group in atari, but then W10 at T11 would kill black.

What am I missing?

Thanks!
Image
User avatar
Dusk Eagle
Gosei
Posts: 1758
Joined: Tue Apr 20, 2010 4:02 pm
Rank: 4d
GD Posts: 0
Has thanked: 378 times
Been thanked: 375 times

Re: Capture race in Shotwell

Post by Dusk Eagle »

It seems they made a mistake in the text. It should say, "Black dies". To put things in context for everyone, this is the position in question:

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

:wc: was just played as a ko threat. If black responds at 'a', finishing the ko, then he loses the [sl=capturingrace]semeai[/sl] as shown in kukula's diagram. So instead, black must play as below, and the ko continues:

Click Here To Show Diagram Code
[go]$$Bc
$$ ----------------
$$ . . . . . . . . |
$$ . . O O X . . . |
$$ . . O X . . . . |
$$ . . O X , X . . |
$$ . O X O . . . . |
$$ . O X X X . 1 . |
$$ . X O O X X O . |
$$ . X O O O O O . |
$$ . . X O . O X O |
$$ X . X O O X 2 X |
$$ X . O X X X X . |
$$ . O . O X . . . |
$$ . . . . . . . . |[/go]
We don't know who we are; we don't know where we are.
Each of us woke up one moment and here we were in the darkness.
We're nameless things with no memory; no knowledge of what went before,
No understanding of what is now, no knowledge of what will be.
kukula
Dies in gote
Posts: 26
Joined: Thu Jul 29, 2010 5:26 am
Rank: KGS 22 kyu
GD Posts: 0
KGS: kukula
Location: USA: New York State
Contact:

Re: Capture race in Shotwell

Post by kukula »

Dusk Eagle wrote: black must play as below,


Ah, right, that's what the text says, black must play as you show, and the variation is given to show why. I.e. if black plays some other way, it must be black that gets hurt. So the text really should say "Black dies"!

Hey, there is hope! I might start understanding little bits of this game!

Thanks again!
Image
xed_over
Oza
Posts: 2264
Joined: Mon Apr 19, 2010 11:51 am
Has thanked: 1179 times
Been thanked: 553 times

Re: Capture race in Shotwell

Post by xed_over »

Post Reply