Tsumego from Breakthrough prob 1

For lessons, as well as threads about specific moves, and anything else worth studying.
Post Reply
User avatar
cyclops
Lives in sente
Posts: 801
Joined: Mon May 10, 2010 3:38 pm
Rank: KGS 7 kyu forever
GD Posts: 460
Location: Amsterdam (NL)
Has thanked: 353 times
Been thanked: 107 times
Contact:
Contact cyclops

Tsumego from Breakthrough prob 1

Post by cyclops »

I'm reading "The breakthrough to Shodan". Not that I have any hopes.
I'm not sure about the first problem in Ch 9.

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


The question is: what is B's best endgame move.

The wrong answer is here:
Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . . . . .
$$ | . X X . . . . . . .
$$ | . O X . . . . . . .
$$ | . O O X . . . . . .
$$ | 6 . O X . . . . . .
$$ | . O X X . O . . . X
$$ | . 4 O 3 X O . . . .
$$ | . 2 1 . X . . . . .
$$ | . 5 . . . . . . . .
$$ +---------------------[/go]


The right answer is:
B1@2 in the previous diagram because W cannot risk W2@1.
Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . . . . .
$$ | . X X . . . . . . .
$$ | . O X . . . . . . .
$$ | . O O X . . . . . .
$$ | . . O X . . . . . .
$$ | . O X X . O . . . X
$$ | c 3 O . X O . . . .
$$ | a 1 2 . X . . . . .
$$ | . b . . . . . . . .
$$ +---------------------[/go]

W4@b next is refuted in the book. W4@c is refuted by B5@a ( I think ). But what about W4@a?


My guess:
Click Here To Show Diagram Code
[go]$$cW4@a,W6@b,B7@c
$$ | . . . . . . . . . .
$$ | . X X . . . . . . .
$$ | d O X . . . . . . .
$$ | . O O X . . . . . .
$$ | 0 . O X . . . . . .
$$ | 8 O X X . O . . . X
$$ | 5 3 O . X O . . . .
$$ | a 1 2 . X . . . . .
$$ | 7 b 9 e f . . . . .
$$ +---------------------[/go]


W4@a,W6@b
B11@d next will give B his not so one sided ko in which he needs the first threat.


correct?
I think I am so I think I am.
Top
User avatar
Cassandra
Lives in sente
Posts: 1326
Joined: Wed Apr 28, 2010 11:33 am
Rank: German 1 Kyu
GD Posts: 0
Has thanked: 14 times
Been thanked: 153 times

Re: Tsumego from Breakthrough prob 1

Post by Cassandra »

cyclops wrote:correct?

White will connect with :w8: at :b9: , thereafter capture the Ko in the corner first.

But because this is an endgame problem, Ko is no option for White anyway.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Top
User avatar
zinger
Lives in gote
Posts: 305
Joined: Wed Apr 21, 2010 5:49 am
Rank: hopeless
GD Posts: 0
Has thanked: 1 time
Been thanked: 16 times

Re: Tsumego from Breakthrough prob 1

Post by zinger »

What about :b5: at :w8: ?
Main Entry: zing·er Pronunciation: \ˈziŋ-ər\
1 : something causing or meant to cause interest, surprise, or shock
2 : a pointed witty remark or retort
Top
User avatar
Cassandra
Lives in sente
Posts: 1326
Joined: Wed Apr 28, 2010 11:33 am
Rank: German 1 Kyu
GD Posts: 0
Has thanked: 14 times
Been thanked: 153 times

Re: Tsumego from Breakthrough prob 1

Post by Cassandra »

zinger wrote:What about :b5: at :w8: ?

Ends in Ko also.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Top
User avatar
cyclops
Lives in sente
Posts: 801
Joined: Mon May 10, 2010 3:38 pm
Rank: KGS 7 kyu forever
GD Posts: 460
Location: Amsterdam (NL)
Has thanked: 353 times
Been thanked: 107 times
Contact:
Contact cyclops

Re: Tsumego from Breakthrough prob 1

Post by cyclops »

It took me some time to digest. But here is what I learnt:
The solutions of the book, of Cassandra and of zinger all leads to ko with Black capturing first. They are all three ( equally) good refutations for W's blocking move @2. W shouldn't risk ko for some yosepoints.

book's refutation:
Click Here To Show Diagram Code
[go]$$cW6 cannot be at a.
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | 6 a O X . . .
$$ | 5 O X X . O .
$$ | . 3 O . X O .
$$ | . 1 2 . X . .
$$ | . 4 . . . . .
$$ +---------------[/go]


Cassandra:
Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | 0 . O X . . .
$$ | 9 O X X . O .
$$ | 5 3 O . X O .
$$ | . 1 2 . X . .
$$ | 7 6 8 . . . .
$$ +---------------[/go]


Zinger:
Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | 8 . O X . . .
$$ | 7 O X X . O .
$$ | . 3 O . X O .
$$ | 4 1 2 . X . .
$$ | . 5 6 . . . .
$$ +---------------[/go]
I think I am so I think I am.
Top
ethanb
Lives in gote
Posts: 355
Joined: Sat Apr 24, 2010 10:15 am
Rank: AGA 2d
GD Posts: 0
IGS: ethanb
Has thanked: 52 times
Been thanked: 43 times

Re: Tsumego from Breakthrough prob 1

Post by ethanb »

cyclops wrote:It took me some time to digest. But here is what I learnt:
The solutions of the book, of Cassandra and of zinger all leads to ko with Black capturing first. They are all three ( equally) good refutations for W's blocking move @2. W shouldn't risk ko for some yosepoints.

book's refutation:
Click Here To Show Diagram Code
[go]$$cW6 cannot be at a.
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | 6 a O X . . .
$$ | 5 O X X . O .
$$ | . 3 O . X O .
$$ | . 1 2 . X . .
$$ | . 4 . . . . .
$$ +---------------[/go]


Cassandra:
Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | 0 . O X . . .
$$ | 9 O X X . O .
$$ | 5 3 O . X O .
$$ | . 1 2 . X . .
$$ | 7 6 8 . . . .
$$ +---------------[/go]


Zinger:
Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | 8 . O X . . .
$$ | 7 O X X . O .
$$ | . 3 O . X O .
$$ | 4 1 2 . X . .
$$ | . 5 6 . . . .
$$ +---------------[/go]



One of these things is not like the other...

"Zinger's" diagram above is not a solution - white will connect with 8.
Top
User avatar
zinger
Lives in gote
Posts: 305
Joined: Wed Apr 21, 2010 5:49 am
Rank: hopeless
GD Posts: 0
Has thanked: 1 time
Been thanked: 16 times

Re: Tsumego from Breakthrough prob 1

Post by zinger »

One of these things is not like the other...

"Zinger's" diagram above is not a solution - white will connect with 8.


True enough. But what I meant was:

Click Here To Show Diagram Code
[go]$$c
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | . . O X . . .
$$ | 5 O X X . O .
$$ | . 3 O . X O .
$$ | 4 1 2 . X . .
$$ | . . . . . . .
$$ +---------------[/go]
Main Entry: zing·er Pronunciation: \ˈziŋ-ər\
1 : something causing or meant to cause interest, surprise, or shock
2 : a pointed witty remark or retort
Top
ethanb
Lives in gote
Posts: 355
Joined: Sat Apr 24, 2010 10:15 am
Rank: AGA 2d
GD Posts: 0
IGS: ethanb
Has thanked: 52 times
Been thanked: 43 times

Re: Tsumego from Breakthrough prob 1

Post by ethanb »

zinger wrote:
One of these things is not like the other...

"Zinger's" diagram above is not a solution - white will connect with 8.


True enough. But what I meant was:

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


That's why I put your name in quotes instead of just saying "Zinger's diagram." He had it labeled as yours but it wasn't. :)
Top
User avatar
cyclops
Lives in sente
Posts: 801
Joined: Mon May 10, 2010 3:38 pm
Rank: KGS 7 kyu forever
GD Posts: 460
Location: Amsterdam (NL)
Has thanked: 353 times
Been thanked: 107 times
Contact:
Contact cyclops

Re: Tsumego from Breakthrough prob 1

Post by cyclops »

He (cyclops) apologizes for misusing Zingers name. Don't know how he got so confused.
But then his (Z's) true move (B5 ) is suboptimal because W gets to make the first ko capture.
Click Here To Show Diagram Code
[go]$$cW4@a
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | . 6 O X . . .
$$ | 5 O X X . O .
$$ | 7 3 O . X O .
$$ | a 1 2 . X . .
$$ | 9 8 0 . . . .
$$ +---------------[/go]
( W7@8 -> B8@10 : threatens fatal atari next @7 or above 5)
Or maybe cyclops is myopic beyond repair?

BTW, the initial position is discussed also in "Basic Techniques of Go" by Haruyama & Nagahara ( Ch 5, dia 43, p 101 ).
I think I am so I think I am.
Top
ethanb
Lives in gote
Posts: 355
Joined: Sat Apr 24, 2010 10:15 am
Rank: AGA 2d
GD Posts: 0
IGS: ethanb
Has thanked: 52 times
Been thanked: 43 times

Re: Tsumego from Breakthrough prob 1

Post by ethanb »

cyclops wrote:He (cyclops) apologizes for misusing Zingers name. Don't know how he got so confused.
But then his (Z's) true move (B5 ) is suboptimal because W gets to make the first ko capture.
Click Here To Show Diagram Code
[go]$$cW4@a
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | . 6 O X . . .
$$ | 5 O X X . O .
$$ | 7 3 O . X O .
$$ | a 1 2 . X . .
$$ | 9 8 0 . . . .
$$ +---------------[/go]
( W7@8 -> B8@10 : threatens fatal atari next @7 or above 5)
Or maybe cyclops is myopic beyond repair?

BTW, the initial position is discussed also in "Basic Techniques of Go" by Haruyama & Nagahara ( Ch 5, dia 43, p 101 ).



Haha, sorry - ethanb has a hard time judging what's polite in terms of pronouns in a forum like this. Better to use names. :)

But 9 can be a hane on the outside, then white will have to throw in to start the ko (so black captures first anyway, as well as making it a direct ko rather than approach-move.)
Top
User avatar
cyclops
Lives in sente
Posts: 801
Joined: Mon May 10, 2010 3:38 pm
Rank: KGS 7 kyu forever
GD Posts: 460
Location: Amsterdam (NL)
Has thanked: 353 times
Been thanked: 107 times
Contact:
Contact cyclops

Re: Tsumego from Breakthrough prob 1

Post by cyclops »

Click Here To Show Diagram Code
[go]$$cW4@a
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | . 6 O X . . .
$$ | 5 O X X . O .
$$ | 7 3 O . X O .
$$ | 4 1 2 . X . .
$$ | . 8 . . . . .
$$ +---------------[/go]

ethanb wrote:Haha, sorry - ethanb has a hard time judging what's polite in terms of pronouns in a forum like this. Better to use names. :)

But 9 can be a hane on the outside, then white will have to throw in to start the ko (so black captures first anyway, as well as making it a direct ko rather than approach-move.)


No need to say sorry; Cyclops was not offended. I am confused about your last remark. W8 is an atari and B has no choice but to play in the very corner. Or do we talk different diagrams?
I think I am so I think I am.
Top
ethanb
Lives in gote
Posts: 355
Joined: Sat Apr 24, 2010 10:15 am
Rank: AGA 2d
GD Posts: 0
IGS: ethanb
Has thanked: 52 times
Been thanked: 43 times

Re: Tsumego from Breakthrough prob 1

Post by ethanb »

cyclops wrote:
Click Here To Show Diagram Code
[go]$$cW4@a
$$ | . . . . . . .
$$ | . X X . . . .
$$ | . O X . . . .
$$ | . O O X . . .
$$ | . 6 O X . . .
$$ | 5 O X X . O .
$$ | 7 3 O . X O .
$$ | 4 1 2 . X . .
$$ | . 8 . . . . .
$$ +---------------[/go]

ethanb wrote:Haha, sorry - ethanb has a hard time judging what's polite in terms of pronouns in a forum like this. Better to use names. :)

But 9 can be a hane on the outside, then white will have to throw in to start the ko (so black captures first anyway, as well as making it a direct ko rather than approach-move.)


No need to say sorry; Cyclops was not offended. I am confused about your last remark. W8 is an atari and B has no choice but to play in the very corner. Or do we talk different diagrams?


We talk late in the evening, I think - I forgot that a marked a stone earlier. :)
Top
Post Reply

Return to “Study Group”