Life In 19x19

Posted: **Tue Feb 06, 2024 2:51 am**

Problem #39, Black to play.

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

Answer:

Posted: **Fri Mar 01, 2024 6:21 am**

Problem #40, White to play. I've probably seen the problem before, but forgot it.

Click Here To Show Diagram Code: [go]Wc $$ | . . . O O X . O . O . X $$ | . . O O X O X . . . . X $$ | . O . . X O . X X X X . $$ | . X O O X . O O O O X . $$ | . X X X O O . . . . O O $$ | . . . . X X O X . . . . $$ | . . . . . . O . . . . . $$ -------------------------[/go]

Posted: **Sat Mar 02, 2024 12:58 pm**

Yeah, this one shows up in life and death manuals. I learned it as part of the J-group collection.

Posted: **Sat Mar 02, 2024 6:13 pm**

Posted: **Mon Mar 04, 2024 12:26 am**

Problem #41, Black to live.

Click Here To Show Diagram Code: [go]$$Bc Black to live $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . X X O O . . . . . . . X O . . . . | $$ | . . X O . X O . . . . . X X X O O O . | $$ | . . X O . . . . . O . . . . O X X O . | $$ | . . . O . . . . . . . . . . X . . X . | $$ | . . X X . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . , X . . . . , . . . . . , . . . | $$ | . . O O X O . . . . . . . . . O . . . | $$ | . . . X O O . . . . . . . . . . . . . | $$ | . W . X O X X . . . . . . . O . . . . | $$ | . . X . X O . X . . . . . X O X . . . | $$ | . . . X . O . . . . X . X . X O O . . | $$ | . X X O . . O . X , . O . . X , . . . | $$ | . X O O . O X . X O . . . O . X X O . | $$ | . O . . O X . X O O . . . . O O X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Answer:

Posted: **Mon Mar 25, 2024 4:55 am**

Problem #41, Black to kill the upper left corner. Not very difficult but it was a blitz game and I failed completely.

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

Posted: **Mon Mar 25, 2024 3:01 pm**

Cute!

What I might have done in a blitz game

What I can see when I think for a minute

Posted: **Tue Mar 26, 2024 9:32 am**

Not exactly tsumego, but you might find this interesting https://realgoproblems.com/

Posted: **Tue Mar 26, 2024 4:08 pm**

mart900 wrote:Not exactly tsumego, but you might find this interesting https://realgoproblems.com/

Discussion in the other thread at https://lifein19x19.com/viewtopic.php?f=9&t=19425

Posted: **Thu May 30, 2024 2:05 am**

Problem #42, what can White to?

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O . . . . . . . . . X X O B . . . | $$ | . . O X X . X X X . X X O X O . O O . | $$ | . . . O . X O . O O . . O . X X X X . | $$ | . . . . . O . O . . . . . . . . . . . | $$ | . . O O O . . . . . . . . . . . O . . | $$ | . . X X O X X . X . . . . . . . O . . | $$ | . . X O X . O X . X . . . . . O . O . | $$ | . . X O X . X . . X O . . . X X O . . | $$ | . . . O O O O X X O . . . X O O X . . | $$ | . . O . O X O O O . . . . . . O X . . | $$ | . . . . O X . X O . . . . . X O O . . | $$ | . . X O . X . X O . . . . . . X O . . | $$ | . . X . . X . O . O . . . . . X O . . | $$ | . . . . . . . . O X X . . . . X X O . | $$ | . . . X X X O O X , . . . . . X O O . | $$ | . . X O O O O X . X . . . X . . X O . | $$ | . . X . . . O X . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Answer

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

If Black a then White b and White has a ko to kill black stones in order to survive.

Posted: **Tue Jun 11, 2024 12:16 pm**

jlt wrote:Problem #42, what can White to?

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

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

If Black a then White b and White has a ko to kill black stones in order to survive.

If I'm understanding this right, your "Black a then White b" ends up as a multi-step ko that is disadvantageous to white.

Initially I thought that this would be better:

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

Then 7 captures at 3 to start the ko. But this is also multi-step, and maybe the threat at b doesn't work.

It's interesting to me because I mentally went down several different paths that I thought were better than your solution, only to eventually convince myself that your solution looks better.

Posted: **Mon Oct 07, 2024 5:57 am**

Problem #43, White to play. Can White kill the group on the left?

Click Here To Show Diagram Code: [go]$$Wc White to play $$ ------------------- $$ | . . . . . . . . X $$ | . . . . . . O O O $$ | . . . . . O O X X $$ | . . . O . O . X . $$ | . O O . . O X . O $$ | . X X O O X X X X $$ | . . X X X O X O O $$ | . . . . . O O X . $$ | . X O X . . O X . $$ | X O X X . O . X O $$ | . O X O O O O O X $$ | . O O O X O X X . $$ | . . X O X X O X X $$ | . O O . X O O X O[/go]

Posted: **Mon Oct 07, 2024 2:18 pm**

Posted: **Wed Oct 09, 2024 1:21 am**

Posted: **Thu May 01, 2025 12:13 am**

Problem #44, White to kill the central group.

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

I modified the position slightly compared to the game to avoid some complication. The problem is not hard but I played a wrong move.

Life In 19x19

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