It is currently Thu Mar 28, 2024 8:04 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
Offline
 Post subject: Dual ladder breaker
Post #1 Posted: Mon Jan 10, 2022 4:38 am 
Lives in sente

Posts: 1236
Liked others: 21
Was liked: 57
Rank: 1d
Click Here To Show Diagram Code
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X . O O X X O X . X X X . |
$$ | . . . . . . . . O X X O O X . . . . . |
$$ | . . . . . . . . X X O O X . . . . . . |
$$ | . . . . . . . 1 a b O X . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

This position appears in https://senseis.xmp.net/?TheFirstRecord ... derBreaker dealing with dual ladder breaker.
the move :w1: is given as the key move to save the two white groups threatened to be captured in a ladder.
My question is the following : instead of the move :w1: can white save her two groups of stones by playing at "a" or even "b" ?

Top
 Profile  
 
Offline
 Post subject: Re: Dual ladder breaker
Post #2 Posted: Mon Jan 10, 2022 7:06 am 
Lives in sente
User avatar

Posts: 914
Liked others: 391
Was liked: 162
Rank: German 2 dan
'a' might work, but 'b' is countered by 'a', I think.

_________________
A good system naturally covers all corner cases without further effort.

Top
 Profile  
 
Offline
 Post subject: Re: Dual ladder breaker
Post #3 Posted: Mon Jan 10, 2022 7:34 am 
Lives in sente

Posts: 1236
Liked others: 21
Was liked: 57
Rank: 1d
Harleqin wrote:
'a' might work, but 'b' is countered by 'a', I think.

Let's try a move at "b":
Click Here To Show Diagram Code
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X . O O X X O X . X X X . |
$$ | . . . . . . . . O X X O O X . . . . . |
$$ | . . . . . . . . X X O O X . . . . . . |
$$ | . . . . . . . b 2 1 O X . . . . . . . |
$$ | . . . . . . . a . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Now is a white move at "a" or "b" not again a dual ladder breaker?

Top
 Profile  
 
Offline
 Post subject: Re: Dual ladder breaker
Post #4 Posted: Mon Jan 10, 2022 8:51 am 
Lives in sente
User avatar

Posts: 914
Liked others: 391
Was liked: 162
Rank: German 2 dan
Nice! What about 'c'? ;-)

_________________
A good system naturally covers all corner cases without further effort.

Top
 Profile  
 
Offline
 Post subject: Re: Dual ladder breaker
Post #5 Posted: Mon Jan 10, 2022 9:02 am 
Lives in sente

Posts: 1236
Liked others: 21
Was liked: 57
Rank: 1d
Harleqin wrote:
Nice! What about 'c'? ;-)

Where is "c"?

Top
 Profile  
 
Offline
 Post subject: Re: Dual ladder breaker
Post #6 Posted: Mon Jan 10, 2022 11:31 am 
Lives in sente

Posts: 1236
Liked others: 21
Was liked: 57
Rank: 1d
Harleqin wrote:
Nice! What about 'c'? ;-)

Click Here To Show Diagram Code
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X . O O X X O X . X X X . |
$$ | . . . . . . . . O X X O O X . . . . . |
$$ | . . . . . . . . X X O O X . . . . . . |
$$ | . . . . . . . . X O O X . . . . . . . |
$$ | . . . . . . . . 1 . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
I guess you have in mind this move :w1: . I agree it works also to save the two white groups.
BTW this move :w1: is perhaps the best one because if black tries to continue to threaten the two white groups of stones then black will weaken more and more her position:
Click Here To Show Diagram Code
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X 5 O O X X O X . X X X . |
$$ | . . . . . . . . O X X O O X . . . . . |
$$ | . . . . . . . 4 X X O O X . . . . . . |
$$ | . . . . . . . 3 X O O X . . . . . . . |
$$ | . . . . . . . 2 1 . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Black cannot hope to capture a white group by :b2: as shown in this diagram above.

It remains only the following sequence:
Click Here To Show Diagram Code
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X 2 O O X X O X . X X X . |
$$ | . . . . . . 4 3 O X X O O X . . . . . |
$$ | . . . . . . 7 5 X X O O X . . . . . . |
$$ | . . . . . . . 6 X O O X . . . . . . . |
$$ | . . . . . . . 8 1 . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
But white can continue in the same way by
Click Here To Show Diagram Code
[go]$$Wm9
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X X O O X X O X . X X X . |
$$ | . . . . . . X O O X X O O X . . . . . |
$$ | . . . . . . O O X X O O X . . . . . . |
$$ | . . . . . . 1 X X O O X . . . . . . . |
$$ | . . . . . 3 2 X O 5 4 . . . . . . . . |
$$ | . . . . . . 0 9 7 6 . . . . . . . . . |
$$ | . . . , . . . . 8 , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code
[go]$$Wm19
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X X O O X X O X . X X X . |
$$ | . . . . . . X O O X X O O X . . . . . |
$$ | . . . . . 6 O O X X O O X . . . . . . |
$$ | . . . . 8 7 O X X O O X . . . . . . . |
$$ | . . . 0 9 O X X O O X . . . . . . . . |
$$ | . . . . . 2 X O O X . . . . . . . . . |
$$ | . . . , . 4 3 1 X , . . . . . , . . . |
$$ | . . . . . 5 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code
[go]$$Wm29
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X X O O X X O X . X X X . |
$$ | . . . . . . X O O X X O O X . . . . . |
$$ | . . . . . X O O X X O O X . . . . . . |
$$ | . . . . X O O X X O O X . . . . . . . |
$$ | . . . X O O X X O O X . . . . . . . . |
$$ | . . . 3 1 X X O O X . . . . . . . . . |
$$ | . . . , 2 X O O X , . . . . . , . . . |
$$ | . . . . 4 O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code
[go]$$Wm33 note : instead of :w33: white can play at "a"
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O X X X X . . . . O . |
$$ | . . . . . O O X X O O O X O O O O X . |
$$ | . . . O . . X X O O X X O X . X X X . |
$$ | . . . . . . X O O X X O O X . . . . . |
$$ | . . . . . B O O X X O O B . . . . . . |
$$ | . . . . B O O X X O O B . . . . . . . |
$$ | . . . B O O X X O O B . . . . . . . . |
$$ | . . . O O X X O O B . . . . . . . . . |
$$ | . . . , X X O O B , . . . . . , . . . |
$$ | . . . a X O . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
You can see in this diagram that by continuing a little the ladder white has created the marked weak stones, just like a simple ladder which does not work. With this in mind isn't it a good idea for white to play like this?


This post by Gérard TAILLE was liked by: Harleqin
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group