Move 9: Black played the marked stone. What can White do? What should Black have played instead of the marked stone?
$$W
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$$ | . . . . , . O . . |
$$ | . . . O O . . . . |
$$ | . . B . X . X . . |
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$$ ---------------------
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[go]$$W
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$$ | . . . . , . O . . |
$$ | . . . O O . . . . |
$$ | . . B . X . X . . |
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$$ ---------------------[/go]
Move 48: White has just played the marked stone. Black has four possibilities to save his two stones. Which are these, and which is the best?
$$B
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$$ | . . . . . . . . . |
$$ | . . . W . . X X . |
$$ | . X . O X X O . . |
$$ | . . X X O O . O . |
$$ | . . . O . . . . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
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$$ ---------------------
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[go]$$B
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$$ | . . . . . . . . . |
$$ | . . . W . . X X . |
$$ | . X . O X X O . . |
$$ | . . X X O O . O . |
$$ | . . . O . . . . . |
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$$ ---------------------[/go]
Move 68: How can Black clean up the upper left corner in the simplest, cleanest way?
$$B
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$$ | . . . . . . . . . |
$$ | . . O O X X X X X |
$$ | . O X O X O O O . |
$$ | . X X X O O . . O |
$$ | . . . X X X O O . |
$$ | . . O X O O . . . |
$$ | . . . O . . . . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ ---------------------
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[go]$$B
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$$ | . . . . . . . . . |
$$ | . . O O X X X X X |
$$ | . O X O X O O O . |
$$ | . X X X O O . . O |
$$ | . . . X X X O O . |
$$ | . . O X O O . . . |
$$ | . . . O . . . . . |
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$$ ---------------------[/go]
Move 72: Does Black need to play once more in the upper left corner?
$$B
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$$ | . . . . . . . . . |
$$ | . X O O X X X X X |
$$ | X . X O X O O O . |
$$ | . X X X O O . . O |
$$ | . O . X X X O O . |
$$ | . . O X O O . . . |
$$ | . O . O . . . . . |
$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
$$ ---------------------
- Click Here To Show Diagram Code
[go]$$B
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$$ | . . . . . . . . . |
$$ | . X O O X X X X X |
$$ | X . X O X O O O . |
$$ | . X X X O O . . O |
$$ | . O . X X X O O . |
$$ | . . O X O O . . . |
$$ | . O . O . . . . . |
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$$ ---------------------[/go]
Move 78: Does Black need to play once more in the upper left corner?
$$B
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$$ | . . X . . . . . . |
$$ | . X O O X X X X X |
$$ | X . X O X O O O . |
$$ | . X X X O O . . O |
$$ | . O . X X X O O . |
$$ | . . O X O O . . . |
$$ | . O . O . . . . . |
$$ | . . . O . . . . . |
$$ | . . . . . . . . . |
$$ ---------------------
- Click Here To Show Diagram Code
[go]$$B
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$$ | . . X . . . . . . |
$$ | . X O O X X X X X |
$$ | X . X O X O O O . |
$$ | . X X X O O . . O |
$$ | . O . X X X O O . |
$$ | . . O X O O . . . |
$$ | . O . O . . . . . |
$$ | . . . O . . . . . |
$$ | . . . . . . . . . |
$$ ---------------------[/go]
Move 132: Black's turn. What is the white threat, and how can Black best counter it?
$$B
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$$ | . . . X O . . . . |
$$ | . X X O X . . . . |
$$ | . X O O . . . O . |
$$ | . . . . , . . . . |
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$$ | . . . . . . . . . |
$$ | . . . . . . . . . |
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$$ ---------------------
- Click Here To Show Diagram Code
[go]$$B
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$$ | . . . . . . . . . |
$$ | . . . X O . . . . |
$$ | . X X O X . . . . |
$$ | . X O O . . . O . |
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$$ ---------------------[/go]
A good system naturally covers all corner cases without further effort.