It is currently Thu Apr 25, 2024 4:42 am

View unanswered posts | View active topics View unread posts | View new posts | View your posts


Board index » Improve Your Game » Study Group

All times are UTC - 8 hours [ DST ]



Post new topic Reply to topic  Page 1 of 1
  [ 10 posts ] 
  Print view Previous topic | Next topic 
Author Message
Offline BadukStone
 Post subject: Question about a tesuji-problem
Post #1 Posted: Sat Jun 27, 2015 3:00 pm 
Beginner

Posts: 4
Liked others: 0
Was liked: 0
In Lee Changho's Selected Tesuji Problems, I've encountered a tesuji-problem which, I think, has two solutions (a and b):


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


'a' was the solution given in the book, and I agree with that, but I think 'b' is also the right move.

My question is whether this problem has two solutions or not.
Top
 Profile  
 
Offline Loons
 Post subject: Re: Question about a tesuji-problem
Post #2 Posted: Sat Jun 27, 2015 6:40 pm 
Gosei
User avatar

Posts: 1378
Location: wHam!lton, Aotearoa
Liked others: 253
Was liked: 105
My two cents, in a relatively bad currency:

'b' is, in isolation just worse than 'a' if black later decides to sacrifice.

_________________
Revisiting Go - Study Journal
My Programming Blog - About the evolution of my go bot.
Top
 Profile  
 
Offline ez4u
 Post subject: Re: Question about a tesuji-problem
Post #3 Posted: Sun Jun 28, 2015 7:02 am 
Oza
User avatar

Posts: 2401
Location: Tokyo, Japan
Liked others: 2339
Was liked: 1332
Rank: Jp 6 dan
KGS: ez4u
BadukStone wrote:
In Lee Changho's Selected Tesuji Problems, I've encountered a tesuji-problem which, I think, has two solutions (a and b):


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


'a' was the solution given in the book, and I agree with that, but I think 'b' is also the right move.

My question is whether this problem has two solutions or not.

It appears to have at least 3. :)

Interestingly, the Web Go Board extension that I use took your original asymmetrical 10x11 diagram and turned it into a 10x10 (a previously undiscoverd bug?), changing the problem to the situation below. This appears to have only one solution. What is it?
:study:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | a . O X O . . . . . |
$$ | . O O X O . . . . . |
$$ | b O X X O . , . . . |
$$ | X O X . O . . . . . |
$$ | . X X O . . . . . . |
$$ | . . O O . . . . . . |
$$ ---------------------[/go]

_________________
Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21

This post by ez4u was liked by: Bill Spight
Top
 Profile  
 
Offline Knotwilg
 Post subject: Re: Question about a tesuji-problem
Post #4 Posted: Sun Jun 28, 2015 7:11 am 
Oza
User avatar

Posts: 2411
Location: Ghent, Belgium
Liked others: 359
Was liked: 1019
Rank: KGS 2d OGS 1d Fox 4d
KGS: Artevelde
OGS: Knotwilg
Online playing schedule: UTC 18:00 - 22:00
Great catch, Dave!
Top
 Profile  
 
Offline Bill Spight
 Post subject: Re: Question about a tesuji-problem
Post #5 Posted: Sun Jun 28, 2015 8:48 am 
Honinbo

Posts: 10905
Liked others: 3651
Was liked: 3374
Very good, Dave! Better problem than the book!

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.
Top
 Profile  
 
Offline BadukStone
 Post subject: Re: Question about a tesuji-problem
Post #6 Posted: Sun Jun 28, 2015 9:00 am 
Beginner

Posts: 4
Liked others: 0
Was liked: 0
Loons wrote:
My two cents, in a relatively bad currency:

'b' is, in isolation just worse than 'a' if black later decides to sacrifice.


Thanks, that makes sense now that I think about it. :scratch:

ez4u wrote:
This appears to have only one solution. What is it?
:study:


I think :b1: (b) is wrong this time, because the throw-in at :w2: works now:

( :b5: at :w2: )
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | . . O X O . . . . . |
$$ | 4 O O X O . . . . . |
$$ | 1 O X X O . , . . . |
$$ | X O X 6 O . . . . . |
$$ | 2 X X O . . . . . . |
$$ | 3 . O O . . . . . . |
$$ ---------------------[/go]
Top
 Profile  
 
Offline ez4u
 Post subject: Re: Question about a tesuji-problem
Post #7 Posted: Sun Jun 28, 2015 9:32 am 
Oza
User avatar

Posts: 2401
Location: Tokyo, Japan
Liked others: 2339
Was liked: 1332
Rank: Jp 6 dan
KGS: ez4u
BadukStone wrote:
Loons wrote:
My two cents, in a relatively bad currency:

'b' is, in isolation just worse than 'a' if black later decides to sacrifice.


Thanks, that makes sense now that I think about it. :scratch:

ez4u wrote:
This appears to have only one solution. What is it?
:study:


I think :b1: (b) is wrong this time, because the throw-in at :w2: works now:

( :b5: at :w2: )
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | . . O X O . . . . . |
$$ | 4 O O X O . . . . . |
$$ | 1 O X X O . , . . . |
$$ | X O X 6 O . . . . . |
$$ | 2 X X O . . . . . . |
$$ | 3 . O O . . . . . . |
$$ ---------------------[/go]

You are on the right track! So what is the right answer?

_________________
Dave Sigaty
"Short-lived are both the praiser and the praised, and rememberer and the remembered..."
- Marcus Aurelius; Meditations, VIII 21
Top
 Profile  
 
Offline BadukStone
 Post subject: Re: Question about a tesuji-problem
Post #8 Posted: Sun Jun 28, 2015 10:31 am 
Beginner

Posts: 4
Liked others: 0
Was liked: 0
So I believe that :b1: must be at the same spot as in the book:

Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | 1 . O X O . . . . . |
$$ | 7 O O X O . . . . . |
$$ | 3 O X X O . , . . . |
$$ | X O X 4 O . . . . . |
$$ | 5 X X O . . . . . . |
$$ | 6 2 O O . . . . . . |
$$ ---------------------[/go]
Top
 Profile  
 
Offline SoDesuNe
 Post subject: Re: Question about a tesuji-problem
Post #9 Posted: Sun Jun 28, 2015 12:49 pm 
Gosei
User avatar

Posts: 1810
Liked others: 490
Was liked: 365
Rank: KGS 1-dan
Click Here To Show Diagram Code
[go]$$Bc Same problem as before?
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | 1 . O X O . . . . . |
$$ | . O O X O . . . . . |
$$ | . O X X O . , . . . |
$$ | X O X . O . . . . . |
$$ | 2 X X O . . . . . . |
$$ | . . O O . . . . . . |
$$ ---------------------[/go]


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

_________________
My "guide" to become stronger in Go
Top
 Profile  
 
Offline BadukStone
 Post subject: Re: Question about a tesuji-problem
Post #10 Posted: Sun Jun 28, 2015 1:36 pm 
Beginner

Posts: 4
Liked others: 0
Was liked: 0
SoDesuNe wrote:
Click Here To Show Diagram Code
[go]$$Bc Same problem as before?
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | 1 . O X O . . . . . |
$$ | . O O X O . . . . . |
$$ | . O X X O . , . . . |
$$ | X O X . O . . . . . |
$$ | 2 X X O . . . . . . |
$$ | . . O O . . . . . . |
$$ ---------------------[/go]

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

You're right, I overlooked this variation. :-?

Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------
$$ | . . X . . . . . . . |
$$ | . . . . . . . . . . |
$$ | . X X O . . . . . . |
$$ | . O X O . . , . . . |
$$ | 1 . O X O . . . . . |
$$ | 5 O O X O . . . . . |
$$ | . O X X O . , . . . |
$$ | X O X 6 O . . . . . |
$$ | 2 X X O . . . . . . |
$$ | 3 4 O O . . . . . . |
$$ ---------------------[/go]
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 1 of 1
  [ 10 posts ] 

Board index » Improve Your Game » Study Group

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