Tsumegos from real games

jlt · Post by **jlt** » Sat Jan 30, 2021 10:22 am

Problem #16, Black to play.

I was white playing an H9 game and killed the upper left corner. However, Black could have lived. How?

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

lightvector · Post by **lightvector** » Sat Jan 30, 2021 11:42 am

About problem 15 shape, one interesting thing to know, if we adjust the stones a little...

Click Here To Show Diagram Code: [go]$$Bc White status? $$ | . . . , . . . . . , . . . O X X X X . | $$ | . X X X . . O . . . . . . O O X X . . | $$ | . X O X O X . X X . . . . . . X . X . | $$ | . O O O X X . O X . X X O . O O X . . | $$ | . . . . . . . O X O . . . . . . X . . | $$ | . . . . X . X X O X X X X . O O X . . | $$ | . . O O O . . . O O O O . X X X X . . | $$ | . . X X O O O O . . . . . . . X O O . | $$ | . . . . X X X O . . . . . . X O . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ ---------------------------------------[/go]

Now white is alive and there is no ko.

Click Here To Show Diagram Code: [go]$$Bc Exercise for the reader - white to live $$ | . . . , . . . . . , . . . O X X X X . | $$ | . X X X . . O . . . . . . O O X X . . | $$ | . X O X O X . X X . . . . . . X . X . | $$ | . O O O X X . O X . X X O . O O X . . | $$ | . . . . . . . O X O . . . . . . X . . | $$ | . . . . X . X X O X X X X . O O X . . | $$ | . . O O O . . . O O O O . X X X X . . | $$ | . . X X O O O O . . . . . . . X O O . | $$ | . . . . X X X O . . . . . . X O . 2 1 | $$ | . . . . . . . . . . . . . . 3 . O . . | $$ ---------------------------------------[/go]

Although also it requires the marked spots to be free of black stones:

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

To also prevent this sequence:

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

Anyways, this means that the following push is very bad for white, because white's corner goes from alive to black being able to make a ko.

Click Here To Show Diagram Code: [go]$$Wc bad push $$ | . . . , . . . . . , . . . O X X X X . | $$ | . X X X . . O . . . . . . O O X X . . | $$ | . X O X O X . X X . . . . . . X . X . | $$ | . O O O X X . O X . X X O . O O X . . | $$ | . . . . . . . O X O . . . . . . X . . | $$ | . . . . X . X X O X X X X . O O X 2 . | $$ | . . O O O . . . O O O O . X X X X 1 . | $$ | . . X X O O O O . . . . . . . X O O . | $$ | . . . . X X X O . . . . . . X O . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ ---------------------------------------[/go]

jlt · Post by **jlt** » Sat Jan 30, 2021 3:44 pm

In fact you make me realize that Problem #15 is the tripod group with extra leg.

https://senseis.xmp.net/?TripodGroupWithExtraLeg

I had read this page before, but not carefully.

jlt · Post by **jlt** » Mon Feb 01, 2021 12:32 am

Answer to problem #16:

jlt · Post by **jlt** » Sat Feb 06, 2021 2:24 pm

Problem #17, White to play. What is the status of the black group Q7?

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

Answer ?

jlt · Post by **jlt** » Sun Apr 11, 2021 7:28 am

An easy one, that both players missed.

Problem#18, White to play in the lower left corner.

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

Wrong answer:

Correct answer:

jlt · Post by **jlt** » Wed Apr 14, 2021 12:02 pm

Problem#19: not complicated but not my first instinct. White to play.

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

Knotwilg · Post by **Knotwilg** » Thu Apr 15, 2021 2:20 am

jlt · Post by **jlt** » Tue Jun 01, 2021 7:59 am

Problem #20: this one is easy but I hallucinated during the game. White to play.

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

Answer:

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

and

may be interchanged.

Yes after several years of practice I still make confusions between real eyes and false eyes.

jlt · Post by **jlt** » Thu Jun 03, 2021 2:37 am

Problem #21: White to play.

Killing is not very hard but White needs to pay attention to something.

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

Answer:

R8. The point is that Black loses the following capturing race:

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

and then P7 is a connect-and-die.

jlt · Post by **jlt** » Fri Jun 11, 2021 3:24 am

Problem #22, White to play. Does White need to protect the corner?

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

Answer:

jlt · Post by **jlt** » Mon Jun 14, 2021 3:15 pm

Position #23, Black to play. What is the status of the upper left corner?

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

Edit: coincidence, it's one of the daily problems on the app Tsumego Pro.

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

White takes the ko first but Black has a ko threat at "a", so both groups survive.

jlt · Post by **jlt** » Mon Sep 20, 2021 8:18 am

Position #24, White to play.

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

Answer:

jlt · Post by **jlt** » Tue Sep 21, 2021 2:14 am

Position #25, White to live.

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

kvasir · Post by **kvasir** » Tue Sep 21, 2021 3:32 am

Position #25, White to live.

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

Hope this is correct

It was hard to see that

allows the net at

so I looked at a few moves before coming back to

Life In 19x19

Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games

Re: Tsumegos from real games