L & D for professionals

For lessons, as well as threads about specific moves, and anything else worth studying.
User avatar
Magicwand
Tengen
Posts: 4844
Joined: Wed Apr 21, 2010 5:26 am
Rank: Wbaduk 7D
GD Posts: 0
KGS: magicwand
Tygem: magicwand
Wbaduk: rlatkfkd
DGS: magicwand
OGS: magicwand
Location: Mechanicsburg, PA
Has thanked: 62 times
Been thanked: 504 times

L & D for professionals

Post by Magicwand »

for those who want to solve professional level LD problem.
top professionals in Korea(choi chulhan, kim jisuk, and few more) could not solve this problem for 20 minute and gaveup.

but someone claimed that there is an answer to this problem.
lets see if anyone here can solve this problem.
Click Here To Show Diagram Code
[go]$$Wcm1 Prisoners: W=0, B=0
$$ ---------------------------------------
$$ | . . . . . . . . . . X . . . . . . . . |
$$ | . . . . . . . . . O X O O . . . O X . |
$$ | . . . . . . . . . X O X O . O . O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

edit: i cound not solve this and i dont have answer.
i am hoping someone or i can comeup with correct answer soon.
Last edited by Magicwand on Thu Aug 19, 2010 5:42 am, edited 1 time in total.
"The more we think we know about
The greater the unknown"

Words by neil peart, music by geddy lee and alex lifeson
gowan
Gosei
Posts: 1628
Joined: Thu Apr 29, 2010 4:40 am
Rank: senior player
GD Posts: 1000
Has thanked: 546 times
Been thanked: 450 times

Re: L & D for professionals

Post by gowan »

Magicwand wrote:for those who want to solve professional level LD problem.
top professionals in Korea(choi chulhan, kim jisuk, and few more) could not solve this problem for 20 minute and gaveup.

but someone claimed that there is an answer to this problem.
lets see if anyone here can solve this problem.
Click Here To Show Diagram Code
[go]$$Wcm1 Prisoners: W=0, B=0
$$ ---------------------------------------
$$ | . . . . . . . . . . X . . . . . . . . |
$$ | . . . . . . . . . O X O O . . . O X . |
$$ | . . . . . . . . . X O X O . O . O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Black to play right?
User avatar
kirkmc
Lives in sente
Posts: 1072
Joined: Tue Apr 20, 2010 3:51 am
Rank: 5K KGS
GD Posts: 1165
KGS: Dogen
Location: Stratford-upon-Avon, England
Has thanked: 32 times
Been thanked: 70 times
Contact:

Re: L & D for professionals

Post by kirkmc »

How do you know it's even solvable? In other words, assuming it's black to play, are you sure that black can kill?
My blog about Macs and more: Kirkville
User avatar
Magicwand
Tengen
Posts: 4844
Joined: Wed Apr 21, 2010 5:26 am
Rank: Wbaduk 7D
GD Posts: 0
KGS: magicwand
Tygem: magicwand
Wbaduk: rlatkfkd
DGS: magicwand
OGS: magicwand
Location: Mechanicsburg, PA
Has thanked: 62 times
Been thanked: 504 times

Re: L & D for professionals

Post by Magicwand »

gowan wrote:Black to play right?

yes black to play.

i saw the video and many professionals tried :b1: as a first move..and could not solve it. it might help you solve them.

Click Here To Show Diagram Code
[go]$$Bcm1 Prisoners: W=0, B=0
$$ ---------------------------------------
$$ | . . . . . . . . . . X . . 1 . . . . . |
$$ | . . . . . . . . . O X O O . . . O X . |
$$ | . . . . . . . . . X O X O . O . O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
"The more we think we know about
The greater the unknown"

Words by neil peart, music by geddy lee and alex lifeson
User avatar
Magicwand
Tengen
Posts: 4844
Joined: Wed Apr 21, 2010 5:26 am
Rank: Wbaduk 7D
GD Posts: 0
KGS: magicwand
Tygem: magicwand
Wbaduk: rlatkfkd
DGS: magicwand
OGS: magicwand
Location: Mechanicsburg, PA
Has thanked: 62 times
Been thanked: 504 times

Re: L & D for professionals

Post by Magicwand »

kirkmc wrote:How do you know it's even solvable? In other words, assuming it's black to play, are you sure that black can kill?


i am pretty sure there is an answer. according to the video one website made a page dedicated to this problem. i am thinking they will not do that if it has no solution.
"The more we think we know about
The greater the unknown"

Words by neil peart, music by geddy lee and alex lifeson
User avatar
prokofiev
Lives with ko
Posts: 223
Joined: Tue Apr 27, 2010 8:03 pm
Rank: decent sdk
GD Posts: 138
Has thanked: 67 times
Been thanked: 10 times

Re: L & D for professionals

Post by prokofiev »

A few thoughts that are perhaps obvious:

It seems that if you don't play O19, White gets an easy eye:

Click Here To Show Diagram Code
[go]$$Bcm1 Prisoners: W=0, B=0
$$ ---------------------------------------
$$ | . . . . . . . . . , X 2 . 4 . . . . . |
$$ | . . . . . . . . . O X O O . 1 . O X . |
$$ | . . . . . . . . . X O X O . O . O X . |
$$ | . . . , . . . . . , 3 X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Edit: Nevermind. I had some idea about ignoring M19, but it clearly does not work...
User avatar
Numsgil
Lives in gote
Posts: 614
Joined: Wed Apr 21, 2010 10:07 am
Rank: 1 Kyu KGS
GD Posts: 0
KGS: Numsgil
Has thanked: 28 times
Been thanked: 65 times

Re: L & D for professionals

Post by Numsgil »

Hmm, when you dig in to this problem there are some interesting half-sequences to consider. Consider the usual fundamentals for L&D: reduce eye space to a killable shape and then play the vital point.

So let's consider the hane on the right.

This sequence here is bad for white, certainly. So if black hanes here, white can't counter hane and save the stones.

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


So then something like this comes to mind. White dies if he plays like this, too.

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


So what if white falls back?

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


Not a local capture, but we force white to try and live in the center maybe. Assuming play up to here is optimal for either side, is there a trick to contain and kill the white group from here?

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


Anyway, those are my thoughts. Maybe a stronger player can take them and run with it.
User avatar
prokofiev
Lives with ko
Posts: 223
Joined: Tue Apr 27, 2010 8:03 pm
Rank: decent sdk
GD Posts: 138
Has thanked: 67 times
Been thanked: 10 times

Re: L & D for professionals

Post by prokofiev »

Numsgil: In your last diagram, white can play 2 at J17 and make an eye easily.
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: L & D for professionals

Post by Cassandra »

Numsgil wrote:Hmm, when you dig in to this problem there are some interesting half-sequences to consider. Consider the usual fundamentals for L&D: reduce eye space to a killable shape and then play the vital point.

So let's consider the hane on the right.


White will not die with the sequences shown.

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

I suppose White will play :w4: from below.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . X c . 6 X a X b . |
$$ | . . . . . . . . . O X O O . . X O X . |
$$ | . . . . . . . . . X O X O . O O O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

And thereafter with :w6: what has been mentioned to be the vital point of this problem.
Black loses some tempo because he must connect at a and b. And c remains as Sente for White, too.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
User avatar
Numsgil
Lives in gote
Posts: 614
Joined: Wed Apr 21, 2010 10:07 am
Rank: 1 Kyu KGS
GD Posts: 0
KGS: Numsgil
Has thanked: 28 times
Been thanked: 65 times

Re: L & D for professionals

Post by Numsgil »

@Cassandra:

Ah yes. Figured there was a good refutation since it's a hard problem and I'm not a strong L&D-er.

Still, I think that's the right track. Maybe do some other stuff first before the hane. The hane there has a lot of aji. More than it really looks like it should (to my eyes anyway). So I think it's just a matter of figuring out when the time is right to activate it.

...

Are we absolutely sure that 'c' in your diagram is sente? Capturing two stones doesn't give white an eye, after all, since it has a defect. It's just a matter of containing white so he can't make another eye further along the edge. I'm wondering if there's a clever tesuji that would work here.

...

Are there any under the stones play that would be at all useful here?
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . X 2 . 1 X 4 X 5 . |
$$ | . . . . . . . . . O X O O . 3 X O X . |
$$ | . . . . . . . . . X O X O . O O O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . X X . O . 1 2 O . |
$$ | . . . . . . . . . O X O O . O . O X . |
$$ | . . . . . . . . . X O X O a O O O X . |
$$ | . . . , . . . . . , . X X O b . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


The above doesn't work ('a' and 'b' are miai), but it's close (in that if black had one more move here, or a shortage of liberties to take advantage of for the throw in, it would work) and the sort of tricky stuff I'd expect from a hard problem. So maybe do some stuff first to prep for this somehow.

...

Also, what about something like this (both sides ignoring the left black stones in atari). You start a ko (I'm not sure the type name. Two step?). Obviously those black stones in atari sort of muck things up a bit. But if black wins the ko white has no eyes on the right so that's maybe something? Is there a way to then contain white to just a single eye on the left?

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


Nothing quite works yet but I feel like these are some pieces of the puzzle.


@prokofiev:
Hmm, yeah, something like this doesn't work for black.

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


Trying to be tricky doesn't really help either.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . O . O . X X O X . . |
$$ | . . . . . . . . 3 O 1 O O O . O O X . |
$$ | . . . . . . . . 2 6 O X O . O . O X . |
$$ | . . . , . . . . . 4 5 X X O X X X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]
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: L & D for professionals

Post by ethanb »

Q18 is interesting. How does white respond?

Click Here To Show Diagram Code
[go]$$Bcm1 Looks dead
$$ ---------------------------------------
$$ | . . . . . . . . . . X . . . . . . . . |
$$ | . . . . . . . . . O X O O 2 . 1 O X . |
$$ | . . . . . . . . . X O X O . O . O X . |
$$ | . . . , . . . . . , . X X O 3 . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]





Click Here To Show Diagram Code
[go]$$Bcm1 Dead too
$$ ---------------------------------------
$$ | . . . . . . . . . . X 3 . 2 . 6 5 . . |
$$ | . . . . . . . . . O X O O . 7 1 O X . |
$$ | . . . . . . . . . X O X O . O 4 O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]





Click Here To Show Diagram Code
[go]$$Bcm1 Connection back doesn't work
$$ ---------------------------------------
$$ | . . . . . . . . . . X 2 . 4 . 8 7 . . |
$$ | . . . . . . . . . O X O O . 5 1 O X . |
$$ | . . . . . . . . . X O X O . O 6 O X . |
$$ | . . . , . . . . . , 3 X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]



Click Here To Show Diagram Code
[go]$$Bcm1 Ah, tesuji?
$$ ---------------------------------------
$$ | . . . . . . . . . . X 2 . 4 . . . . . |
$$ | . . . . . . . . . O X O O 8 7 1 O X . |
$$ | . . . . . . . . . X O X O 5 O 9 O X . |
$$ | . . . , . . . . . , 3 X X O 6 . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
unkx80
Lives with ko
Posts: 257
Joined: Tue Apr 20, 2010 12:21 am
Rank: Dan player
GD Posts: 0
Location: Singapore
Has thanked: 13 times
Been thanked: 30 times
Contact:

Re: L & D for professionals

Post by unkx80 »

I haven't found any solution yet.

@ethanb: How do you deal with the following?

Click Here To Show Diagram Code
[go]$$Bcm1 Looks dead
$$ ---------------------------------------
$$ | . . . . . . . . . . X 8 . . 6 5 3 7 . |
$$ | . . . . . . . . . O X O O . 4 1 O X . |
$$ | . . . . . . . . . X O X O . O 2 O X . |
$$ | . . . , . . . . . , 9 X X O 0 . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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: L & D for professionals

Post by Cassandra »

@Numsgil:

You have to mind the order of moves ;-)

Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . X . 9 O X . X . . |
$$ | . . . . . . . . . O X O O 7 8 X O X . |
$$ | . . . . . . . . . X O X O . O O O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]


Click Here To Show Diagram Code
[go]$$Wcm10
$$ ---------------------------------------
$$ | . . . . . . . . . . X c X a X b X . . |
$$ | . . . . . . . . . O X O O X O X O X . |
$$ | . . . . . . . . . X O X O 1 O O O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

Black cannot connect at a, because White c is Double-Atari then.
If Black plays c, White gets a Double-Ko at a and b.
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
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: L & D for professionals

Post by ethanb »

unkx80 wrote:I haven't found any solution yet.

@ethanb: How do you deal with the following?

Click Here To Show Diagram Code
[go]$$Bcm1 Looks dead
$$ ---------------------------------------
$$ | . . . . . . . . . . X 8 . . 6 5 3 7 . |
$$ | . . . . . . . . . O X O O . 4 1 O X . |
$$ | . . . . . . . . . X O X O . O 2 O X . |
$$ | . . . , . . . . . , 9 X X O 0 . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


At least I never claimed to not be an idiot :)

But I still feel good about Q18 - I'm going to study it some and see if there's a non-obvious sequence after Q17. Under the stones eye stealing or something, maybe.

Another thought, has anyone looked seriously at capturing immediately to prevent white's forcing move?
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: L & D for professionals

Post by Cassandra »

ethanb wrote:But I still feel good about Q18 - I'm going to study it some and see if there's a non-obvious sequence after Q17. Under the stones eye stealing or something, maybe.


Click Here To Show Diagram Code
[go]$$Bcm1
$$ ---------------------------------------
$$ | . . . . . . . . . . X . . 5 . . 3 . . |
$$ | . . . . . . . . . O X O O . 4 1 O X . |
$$ | . . . . . . . . . X O X O . O 2 O X . |
$$ | . . . , . . . . . , . X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]

There are some problems, where :b5: is the Tesuji.
But here Black cannot do anything on the left, so there is no Miai with the potential Ko on the right.


Preventing White's Sente on the left immediately ...
... will not work, I suppose.
Click Here To Show Diagram Code
[go]$$Bcm1
$$ ---------------------------------------
$$ | . . . . . . . . . . X . . . . . . . . |
$$ | . . . . . . . . . O X O O . 2 . O X . |
$$ | . . . . . . . . . X O X O . O . O X . |
$$ | . . . , . . . . . , 1 X X O . . X . . |
$$ | . . . . . . . . . X . . X O . X . X . |
$$ | . . . . . . . . . . . . X O . X . . . |
$$ | . . . . . . . . . . . . . X X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)
Post Reply