Tsumegos from real games

For lessons, as well as threads about specific moves, and anything else worth studying.
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Knotwilg
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Re: Tsumegos from real games

Post by Knotwilg »

Click Here To Show Diagram Code
[go]$$W White to play
$$ ---------------------------------------
$$ | . . . . . . . . 4 2 3 X . X X . X . . |
$$ | . . . X . . . . X O O O X X X X O O . |
$$ | . . O . . X . . X X B O X O O X O . . |
$$ | . . . O . . . . . , X O X O X X O . . |
$$ | . . . . . . . . . . X O O O O X X O . |
$$ | . . O . . . . . . . B O X X 6 O X O . |
$$ | . . . . . . . . . . X O 7 O O O X O . |
$$ | . . . . . . . . . . X O O O X X X O . |
$$ | . . . . . . . . . . X O X X X X O O . |
$$ | . . . X . . . . O O X O X O W X O O X |
$$ | . . . X O . . . O X . X O . O X O X . |
$$ | . . X O . O O O X X . . . . W X X X 1 |
$$ | . . X O . X X O X O . O O O O O O O 5 |
$$ | . . X O . . . X X O . . X X X X O . . |
$$ | . X O O O X . X . O X . . X . X O . . |
$$ | . X O , O X . . . O . . O X X O . . . |
$$ | . . X O O O X X X O . X O X O O . . . |
$$ | . X . X . O X . X O X . X . X O . . . |
$$ | . . X . . . . . X O . . . X O O . . . |
$$ ---------------------------------------[/go]
The marked stones are outside liberties, incidental to the problem/
Click Here To Show Diagram Code
[go]$$B continuation
$$ ---------------------------------------
$$ | . . . . . . . . X X O X 4 X X . X . . |
$$ | . . . X . . . . X O O O X X X X O O . |
$$ | . . O . . X . . X X B O X O O X O . . |
$$ | . . . O . . . . . , X O X O X X O . . |
$$ | . . . . . . . . . . X O O O O X X O . |
$$ | . . O . . . . . . . B O . 1 3 O X O . |
$$ | . . . . . . . . . . X O O O O O X O . |
$$ | . . . . . . . . . . X O O O X X X O . |
$$ | . . . . . . . . . . X O X X X X O O . |
$$ | . . . X . . . . O O X O X O W X O O X |
$$ | . . . X O . . . O X . X O . O X O X 2 |
$$ | . . X O . O O O X X . . . . W X X X O |
$$ | . . X O . X X O X O . O O O O O O O O |
$$ | . . X O . . . X X O . . X X X X O . . |
$$ | . X O O O X . X . O X . . X . X O . . |
$$ | . X O , O X . . . O . . O X X O . . . |
$$ | . . X O O O X X X O . X O X O O . . . |
$$ | . X . X . O X . X O X . X . X O . . . |
$$ | . . X . . . . . X O . . . X O O . . . |
$$ ---------------------------------------[/go]
White takes first
Click Here To Show Diagram Code
[go]$$W White to play
$$ ---------------------------------------
$$ | . . . . . . . . 4 1 8 X 6 X X 9 X 7 . |
$$ | . . . X . . . . X O O O X X X X O O . |
$$ | . . O . . X . . X X B O X O O X O . . |
$$ | . . . O . . . . . , X O X O X X O . . |
$$ | . . . . . . . . . . X O O O O X X O . |
$$ | . . O . . . . . . . B O X X . O X O . |
$$ | . . . . . . . . . . X O . O O O X O . |
$$ | . . . . . . . . . . X O O O X X X O . |
$$ | . . . . . . . . . . X O X X X X O O 5 |
$$ | . . . X . . . . O O X O X O W X O O X |
$$ | . . . X O . . . O X . X O . O X O X . |
$$ | . . X O . O O O X X . . . . W X X X 2 |
$$ | . . X O . X X O X O . O O O O O O O 3 |
$$ | . . X O . . . X X O . . X X X X O . . |
$$ | . X O O O X . X . O X . . X . X O . . |
$$ | . X O , O X . . . O . . O X X O . . . |
$$ | . . X O O O X X X O . X O X O O . . . |
$$ | . X . X . O X . X O X . X . X O . . . |
$$ | . . X . . . . . X O . . . X O O . . . |
$$ ---------------------------------------[/go]
White will always take a ko to prevent Black from connecting.
Edited diagram 2, voiding jlt's next comment
Last edited by Knotwilg on Fri May 22, 2020 1:29 pm, edited 3 times in total.
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jlt
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Re: Tsumegos from real games

Post by jlt »

Knotwilg, you mistyped what you had in mind in diagram 2 since there are two :w2: on the board and :b7: on an intersection that is already occupied by a white stone.

Anyway I think that :w1: starting from your diagram 1 leads to a ko (this is what happened in my game), while :w1: in your diagram 3 is the correct move, White wins the semeai without needing to fight a ko.
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Re: Tsumegos from real games

Post by jlt »

Problem #8: Black to play. Can Black save the marked stone?
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . O O X . . . |
$$ | . O . B O . . . . , . . O X O X . . . |
$$ | O . O O X O . . . . . O . X O X . . . |
$$ | . O X X X . . . . . . . X . X X O . . |
$$ | . X X . X . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , O . . . . , . . . . . , . . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . O X . |
$$ | . . . . . . . . . . . . . . . . O X . |
$$ | . . X . . . . . . . . . . . . . O X . |
$$ | . . . , O . . . . X . . X . . O X . . |
$$ | . . . O . . . O . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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jlt
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Re: Tsumegos from real games

Post by jlt »

Possible variation:
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 7 3 . . . . . . . . . . . . . . . . |
$$ | . 4 . . 5 O . . . . . . . O O X . . . |
$$ | . O 1 B O 6 . . . , . . O X O X . . . |
$$ | O 2 O O X O . . . . . O . X O X . . . |
$$ | . O X X X . . . . . . . X . X X O . . |
$$ | . X X . X . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]
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Re: Tsumegos from real games

Post by jlt »

Problem #9. I was Black in this game. Between moves 50 and 130 I thought that I had killed the upper left corner. Probably White thought the same as well, as he didn't try to live. When he finally made an attempt at move 130, he didn't make the correct choice.

White to play and save the marked stones.
Click Here To Show Diagram Code
[go]$$Wc White to play and save the marked stones
$$ ---------------------------------------
$$ | . . . . . . . . X . . . . . . . X O . |
$$ | . . . . . . X X . X O . . . O X . O . |
$$ | . . . . X . O X X O O . O O O X X X . |
$$ | . . W W X . . O O , . . . X X X O X . |
$$ | . . . . . . O . X O . . X . X O O O . |
$$ | . . X X . X X O . . . . X X X X O . . |
$$ | . . . . . . . O . . . . X O O O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . X X O . . . X . O O X . . |
$$ | . . X X X . . O . , . O . X O X X . . |
$$ | . . X O . O . . . . . . O O X O . . . |
$$ | . . X O . O . . . . . . . O X O O X . |
$$ | . . O X . . . . . . . . X O X . X . . |
$$ | . . O . . . . . . . . O O X . X . . . |
$$ | . . . . . . . O X . O O X . . . . . . |
$$ | . . . O . . . . O O . X . X . O X . . |
$$ | . . . . O . O O X X O O X . . X . . . |
$$ | . . . O X X X X O X X . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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Knotwilg
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Re: Tsumegos from real games

Post by Knotwilg »

Click Here To Show Diagram Code
[go]$$Wc White to play and save the marked stones
$$ ---------------------------------------
$$ | . . . . . . . . X . . . . . . . X O . |
$$ | . 1 . a . . X X . X O . . . O X . O . |
$$ | . . . . X . O X X O O . O O O X X X . |
$$ | . . W W X . . O O , . . . X X X O X . |
$$ | . b . . . . O . X O . . X . X O O O . |
$$ | . . X X . X X O . . . . X X X X O . . |
$$ | . . . . . . . O . . . . X O O O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . X X O . . . X . O O X . . |
$$ | . . X X X . . O . , . O . X O X X . . |
$$ | . . X O . O . . . . . . O O X O . . . |
$$ | . . X O . O . . . . . . . O X O O X . |
$$ | . . O X . . . . . . . . X O X . X . . |
$$ | . . O . . . . . . . . O O X . X . . . |
$$ | . . . . . . . O X . O O X . . . . . . |
$$ | . . . O . . . . O O . X . X . O X . . |
$$ | . . . . O . O O X X O O X . . X . . . |
$$ | . . . O X X X X O X X . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Does :w1: make miai of A and B?
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Re: Tsumegos from real games

Post by jlt »

Not sure.
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . X . . . . . . . X O . |
$$ | . 1 . 3 4 . X X . X O . . . O X . O . |
$$ | . . . . X . O X X O O . O O O X X X . |
$$ | . . W W X . . O O , . . . X X X O X . |
$$ | . 2 . . . . O . X O . . X . X O O O . |
$$ | . . X X . X X O . . . . X X X X O . . |
$$ | . . . . . . . O . . . . X O O O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |[/go]
and then?
This seems to lead to a ko
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . 8 9 . . . . . X . . . . . . . X O . |
$$ | 0 1 . 3 4 . X X . X O . . . O X . O . |
$$ | . 6 . 5 X . O X X O O . O O O X X X . |
$$ | . 7 W W X . . O O , . . . X X X O X . |
$$ | . 2 . . . . O . X O . . X . X O O O . |
$$ | . . X X . X X O . . . . X X X X O . . |
$$ | . . . . . . . O . . . . X O O O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |[/go]
Katago suggests another move
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | 9 . . . . . . . X . . . . . . . X O . |
$$ | 6 5 . 1 3 4 X X . X O . . . O X . O . |
$$ | . 7 . 8 X . O X X O O . O O O X X X . |
$$ | . . W W X . . O O , . . . X X X O X . |
$$ | . 2 . . . . O . X O . . X . X O O O . |
$$ | . . X X . X X O . . . . X X X X O . . |
$$ | . . . . . . . O . . . . X O O O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |[/go]
It is really necessary for Black to block at :4:, otherwise a variation like this can happen:
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . 8 . X . . . . . . . X O . |
$$ | . . . 1 3 5 X X . X O . . . O X . O . |
$$ | . 4 . . X 6 O X X O O . O O O X X X . |
$$ | . . W W X . 7 O O , . . . X X X O X . |
$$ | . 2 . . 9 . O . X O . . X . X O O O . |
$$ | . . X X . X X O . . . . X X X X O . . |
$$ | . . . . . . . O . . . . X O O O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |[/go]
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Re: Tsumegos from real games

Post by jlt »

Problem #10, White to play. What is the status of the C10 group?
Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O . . O O . . . . . . . . O O O . . |
$$ | . . . . O X . X . . . O O O X O X . . |
$$ | X O O O X X . . . , . O X X X X . X . |
$$ | . X X . . . . . . . X O . . . X . . . |
$$ | . . X . X . . . . . . O O . X O O . . |
$$ | . O . . O X . X . X . O X X . O X . . |
$$ | . . O O O X . . . . X . . . O O . . . |
$$ | X . O X O O . O X X . . X X X O O . . |
$$ | . . O X O . O X X O . . . . . O X . . |
$$ | O O X X X . X O O O . . O O O O . X . |
$$ | . X X . . X . . X O O O X X X . . . . |
$$ | . . . X . X . X . O X X . . . . X . . |
$$ | . . X O O O O . O . . . . . X . . X . |
$$ | . . X O . . O . O . O O . . . . X . O |
$$ | . . X O X O X X . , X O . X O O X O . |
$$ | . . O O X X . . X . X O . X X O O . O |
$$ | . . . . X . . . . . . X X O X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ ---------------------------------------[/go]
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Re: Tsumegos from real games

Post by jlt »

Answer:
It's a ko.
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O . . O O . . . . . . . . O O O . . |
$$ | . . . . O X . X . . . O O O X O X . . |
$$ | X O O O X X . . . , . O X X X X . X . |
$$ | 2 X X . . . . . . . X O . . . X . . . |
$$ | 1 5 X . X . . . . . . O O . X O O . . |
$$ | 8 O 7 . O X . X . X . O X X . O X . . |
$$ | 3 6 O O O X . . . . X . . . O O . . . |
$$ | X 4 O X O O . O X X . . X X X O O . . |
$$ | . . O X O . O X X O . . . . . O X . . |
$$ | O O X X X . X O O O . . O O O O . X . |
$$ | . X X . . X . . X O O O X X X . . . . |
$$ | . . . X . X . X . O X X . . . . X . . |
$$ | . . X O O O O . O . . . . . X . . X . |
$$ | . . X O . . O . O . O O . . . . X . O |
$$ | . . X O X O X X . , X O . X O O X O . |
$$ | . . O O X X . . X . X O . X X O O . O |
$$ | . . . . X . . . . . . X X O X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ ---------------------------------------[/go]
White has local ko threats: capture A16 or capture F13.

In order to live, White just needs to ignore one ko threat and then can live with B10: after :w9: ko threat, :b10: responds, :w11: takes ko, :b12: ko threat, then White is alive (if Black a then White b).
Click Here To Show Diagram Code
[go]$$Wm11
$$ | X X X . . . . . . . X O . . . X . . . |
$$ | O O X . X . . . . . . O O . X O O . . |
$$ | a O O . O X . X . X . O X X . O X . . |
$$ | 1 X O O O X . . . . X . . . O O . . . |
$$ | X X O X O O . O X X . . X X X O O . . |
$$ | b 3 O X O . O X X O . . . . . O X . . |
$$ | O O X X X . X O O O . . O O O O . X . |
$$ | . X X . . X . . X O O O X X X . . . . |
$$ | . . . X . X . X . O X X . . . . X . . |[/go]
Move :w1: is interesting because go problems rarely teach us these kinds of moves. In most go problems, only one group is involved and we don't threaten to connect to another group before living locally.
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Re: Tsumegos from real games

Post by jlt »

Problem #11, White to play.
Click Here To Show Diagram Code
[go]$$Wc
$$ ------------
$$ . X . X . . |
$$ . X . . O . |
$$ X . . O . . |
$$ X . , X O . |
$$ X . . X O . |
$$ . . . O X . |
$$ . X . . X . |
$$ . . . . . . |[/go]
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Re: Tsumegos from real games

Post by Harleqin »

Q18 seems to make miai.
A good system naturally covers all corner cases without further effort.
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Re: Tsumegos from real games

Post by jlt »

Problem #12, Black to play. It seems that Black can kill and that both players (1k Tygem) missed that during all the game.
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . . . . . |
$$ | . . . , O . . . . , . . . . . X . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O . . . . . . . . . . . |
$$ | . . . . . . . O X . . . . . . . . . . |
$$ | . . O . . . . O X . . . . . . . . . . |
$$ | . O O . . . . O X . X X X . . . X . . |
$$ | . X X O O O O X X , O . O X . , . . . |
$$ | X . . X O X X O . O . . O O X X . . . |
$$ | . X X X X X . O . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Answer:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . . . . . |
$$ | . . . , O . . . . , . . . . . X . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O . . . . . . . . . . . |
$$ | . . . . . . . O X . . . . . . . . . . |
$$ | . . O . . . . O X . . . . . . . . . . |
$$ | . O O . . . . O X . X X X . . . X . . |
$$ | . X X O O O O X X , O 1 O X . , . . . |
$$ | X . . X O X X O . O . 2 O O X X . . . |
$$ | . X X X X X . O . . 3 . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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Re: Tsumegos from real games

Post by jlt »

Problem #13: Black to play and kill the bottom group.
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . X . . . . . . . . . X O O . O . |
$$ | . . X O O O . . O X . . . X O . O O X |
$$ | . . X O . . O X O . X . . X X O O X . |
$$ | . . O X O O . O . , . . . X X X X . X |
$$ | . . X X . . . . . X O . O X O . . X . |
$$ | . . . X X X O . . . . O X O O . . . . |
$$ | . . X O O O X X X . O . X X . O X . . |
$$ | . X . X . X O X . O O X X . . O . O . |
$$ | . O X X X O O X X X O O X . . . O . . |
$$ | . . O O O O . O X X O . O X . , . . . |
$$ | . . . . . . . O O X X O O X . . . . . |
$$ | . . . . O X X X O O O . O X . . O . . |
$$ | . . O . . O . . X O O . O X . . O O . |
$$ | . . . . . O X . X X O O X . X X O X . |
$$ | . . . . . O X . . O X X X X . . X X . |
$$ | . . . O O X . . . O . . . . X X O O . |
$$ | . O O X X X . . X . O X X O . X . . . |
$$ | . . X . . . . . X O . O O . O X X . . |
$$ | . . . . . . . . O . . . . . . O . . . |
$$ ---------------------------------------[/go]
Answer:
Click Here To Show Diagram Code
[go]$$Bc Answer
$$ ---------------------------------------
$$ | . . . X . . . . . . . . . X O O . O . |
$$ | . . X O O O . . O X . . . X O . O O X |
$$ | . . X O . . O X O . X . . X X O O X . |
$$ | . . O X O O . O . , . . . X X X X . X |
$$ | . . X X . . . . . X O . O X O . . X . |
$$ | . . . X X X O . . . . O X O O . . . . |
$$ | . . X O O O X X X . O . X X . O X . . |
$$ | . X . X . X O X . O O X X . . O . O . |
$$ | . O X X X O O X X X O O X . . . O . . |
$$ | . . O O O O . O X X O . O X . , . . . |
$$ | . . . . . . . O O X X O O X . . . . . |
$$ | . . . . O X X X O O O . O X . . O . . |
$$ | . . O . . O . . X O O . O X . . O O . |
$$ | . . . . . O X . X X O O X . X X O X . |
$$ | . . . . . O X . . O X X X X . . X X . |
$$ | . . . O O X . . . O . . . . X X O O . |
$$ | . O O X X X . . X 1 O X X O . X . . . |
$$ | . . X . . . . . X O . O O . O X X . . |
$$ | . . . . . . . . O . . . . . . O . . . |
$$ ---------------------------------------[/go]
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jlt
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Re: Tsumegos from real games

Post by jlt »

This ridiculous position is from a blitz game.

Problem #14: Black to play. Which group should Black choose to kill and how?
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . O . . . . . . . . O . . X . X O . |
$$ | . X X O O O . . . . . . . X X . X O . |
$$ | . . . X X X O O O O . O . . . X O O . |
$$ | . . . . . . X X X O . . . . . X X O . |
$$ | . . . . . . . . . . . . . . . X O O . |
$$ | . . . . . X . . X . . . . . . . X . . |
$$ | . . . . . X O . . . . . . . . . . . . |
$$ | . . . X X O . . . X . . . . O O . . . |
$$ | . . X O O . O . O O X . . X O X . . . |
$$ | . . . . . . . . . . X . X X X O O . . |
$$ | . . X . . . O . . O X X O O X X O . . |
$$ | . . . . X O O . . . X O O . O X O . . |
$$ | . . . . . X O X . . X O . O . X . . . |
$$ | . . X X . X X . . . X . . . . X O . . |
$$ | . . O , . O . . . , X O . O O X O . . |
$$ | . . . O . . . O . . X . O . X X O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Answer:
Click Here To Show Diagram Code
[go]$$Bc Answer
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . O . . . . . . . . O . . X . X O . |
$$ | . X X O O O . . . . . . . X X . X O . |
$$ | . . . X X X O O O O . O . . . X O O . |
$$ | . . . . . . X X X O . . . . . X X O . |
$$ | . . . . . . . . . . . . . . . X O O . |
$$ | . . . . . X . . X . . . . . . . X . . |
$$ | . . . . . X O . . . . . . . . . . . . |
$$ | . . . X X O . . . X . . . . O O . . . |
$$ | . . X O O . O . O O X . . X O X . . . |
$$ | . . . . . a . . . . X . X X X O O . . |
$$ | . . X . . . O . . O X X O O X X O . . |
$$ | . . . . X O O . . . X O O . O X O . . |
$$ | . . . . . X O X . . X O . O . X . . . |
$$ | . . X X . X X . . . X . b . . X O . . |
$$ | . . O , . O . . . , X O . O O X O . . |
$$ | . . . O . . . O . . X . O . X X O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
"a" kills a bigger group than "b".
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Re: Tsumegos from real games

Post by jlt »

Problem #15: Black to play. What is the status of the lower right corner?
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . O X X . . X . . |
$$ | . . . O . O . . . . . O O X O O X . . |
$$ | . . O , . . . . O , O X X . X X . . . |
$$ | . O X X . . O . . . O . O X X . . . . |
$$ | . O O X . X X X . . . . O X . X . . . |
$$ | . O X X . . O X . . X O . O X X O . . |
$$ | . O O X . . O . X . . O O O O O . O . |
$$ | . . . X . . . O O O . . O X X X O O . |
$$ | . . . , . . . . . , . . . O X X X X . |
$$ | . X X X . . O . . . . . . O O X X . . |
$$ | . X O X O X . X X . . . . . . X O O X |
$$ | . O O O X X . O X . X X O . O O X X . |
$$ | . . . . . . . O X O . . . . . . X X . |
$$ | . . . . X . X X O X X X X . O O O X . |
$$ | . . O O O . . . O O O O . X X X X O . |
$$ | . . X X O O O O . . . . . . . X O O . |
$$ | . . . . X X X O . . . . . . X O . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc Ko
$$ | . X O X O X . X X . . . . . . X O O X |
$$ | . O O O X X . O X . X X O . O O X X . |
$$ | . . . . . . . O X O . . . . . . X X . |
$$ | . . . . X . X X O X X X X . O O O X . |
$$ | . . O O O . . . O O O O . X X X X O . |
$$ | . . X X O O O O . . . . . . . X O O . |
$$ | . . . . X X X O . . . . . . X O . 2 1 |
$$ | . . . . . . . . . . . . . . 3 . O . . |
$$ ---------------------------------------[/go]
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