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Shusaku game problem

Posted: Sat Oct 16, 2010 8:28 pm
by Exologist
His first game (from Invincible). Trying to figure this out...

Click Here To Show Diagram Code
[go]$$B 19x19 diagram
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . . O . O X . . O . . . O . X . . . |
$$ | . . O O O X . . . , . . . . . X . . . |
$$ | . . . . X X . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . O X . 4 . . O . X . . . 3 . . . |
$$ | . . . O X . . . . . . . . 5 2 1 . 7 . |
$$ | . . . O . . X X O O . X . X . . 6 8 . |
$$ | . . . . . O . . . . X . O O O O . . . |
$$ | . O O . . O X X O O X . O . X X O . . |
$$ | . . X . O O O X X O X . . O . . O . . |
$$ | . . . X X O O O O X O O O X X X X . . |
$$ | . . . . X X X O O X O X O O X . . . . |
$$ | . . . . . . . X X X X X . . O X . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ ---------------------------------------[/go]

Apparently :b1: was an overplay by young Shusaku which gave white time to play a key move at :w4: because after :w8: black still can't kill white. Black played away, but the commentary showed that if black played like below white lives in the following manner because when black plays at a white can respond at b without black able to approach at c.

Click Here To Show Diagram Code
[go]$$B 19x19 diagram
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . . O . O X . . O . . . O . X . . . |
$$ | . . O O O X . . . , . . . . . X . . . |
$$ | . . . . X X . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . O X . O . . O . X . . . X . 1 . |
$$ | . . . O X . . . . . . . . X O X . X . |
$$ | . . . O . . X X O O . X . X . . O O . |
$$ | . . . . . O . . . . X . O O O O . . . |
$$ | . O O . . O X X O O X . O . X X O b . |
$$ | . . X . O O O X X O X . . O . . O . 4 |
$$ | . . . X X O O O O X O O O X X X X 2 c |
$$ | . . . . X X X O O X O X O O X a 8 3 5 |
$$ | . . . . . . . X X X X X . 7 O X 6 9 . |
$$ | . . . . . . . . . X . . . . . . . 0 . |
$$ ---------------------------------------[/go]

But what if Black plays :b5: ? If white plays a then black can pop the eye with b, so I can't see how white can live...

Click Here To Show Diagram Code
[go]$$B 19x19 diagram
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . . O . O X . . O . . . O . X . . . |
$$ | . . O O O X . . . , . . . . . X . . . |
$$ | . . . . X X . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . O X . O . . O . X . . . X . 1 . |
$$ | . . . O X . . . . . . . . X O X . X . |
$$ | . . . O . . X X O O . X . X . b O O . |
$$ | . . . . . O . . . . X . O O O O . a . |
$$ | . O O . . O X X O O X . O . X X O 5 . |
$$ | . . X . O O O X X O X . . O . . O . 4 |
$$ | . . . X X O O O O X O O O X X X X 2 . |
$$ | . . . . X X X O O X O X O O X . . 3 . |
$$ | . . . . . . . X X X X X . . O X . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shusaku game problem

Posted: Sun Oct 17, 2010 12:04 am
by HermanHiddema
Click Here To Show Diagram Code
[go]$$W 19x19 diagram
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . . O . O X . . O . . . O . X . . . |
$$ | . . O O O X . . . , . . . . . X . . . |
$$ | . . . . X X . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . O X . O . . O . X . . . X . X . |
$$ | . . . O X . . . . . . . . X O X . X . |
$$ | . . . O . . X X O O . X . X . B O O . |
$$ | . . . . . O . . . . X . O O O O . W . |
$$ | . O O . . O X X O O X . O . X X O X . |
$$ | . . X . O O O X X O X . . O . . O . O |
$$ | . . . X X O O O O X O O O X X X X O 7 |
$$ | . . . . X X X O O X O X O O X 6 3 X 2 |
$$ | . . . . . . . X X X X X . 9 O X 4 1 5 |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ ---------------------------------------[/go]


After the a-b exchange ( :wc: - :bc: ), white can kill the corner with :w1: through :w9: ( :b8: at :w3: )

White also still has only one eye, but that just means the worst that can happen is seki, which effectively means white is alive.

And given the large number of outside liberties white has, white will win the semeai anyway.

Re: Shusaku game problem

Posted: Sun Oct 17, 2010 10:26 pm
by Exologist
But can't black go here with a and b miai?

Click Here To Show Diagram Code
[go]$$W 19x19 diagram
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . . O . O X . . O . . . O . X . . . |
$$ | . . O O O X . . . , . . . . . X . . . |
$$ | . . . . X X . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . O X . O . . O . X . . . X . X . |
$$ | . . . O X . . . . . . . . X O X . X . |
$$ | . . . O . . X X O O . X . X . B O O . |
$$ | . . . . . O . . . . X . O O O O . W . |
$$ | . O O . . O X X O O X . O . X X O X . |
$$ | . . X . O O O X X O X . . O . . O . O |
$$ | . . . X X O O O O X O O O X X X X O . |
$$ | . . . . X X X O O X O X O O X . 2 X a |
$$ | . . . . . . . X X X X X . b O X . 1 . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ ---------------------------------------[/go]