I just had an exciting win, and my first ever double ko (I think).

I wanted to know if this was an actual viable move that I found, or my opponent just made a mistake. Fine Arts seems to think it was a fluke, but I'm not sure how it is at recognizing groups alive through double ko.

I am talking about B69. Let me know if you think it is a tesuji, or a stupid move. Any general review/comments are also appreciated.

You did well to get the vital point.

But what happens if he gets there first?

Click Here To Show Diagram Code

[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . O . . . , . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . O . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . X . . . . . . . . |
$$ | . . X . . . . . . . . X X . . . . . . |
$$ | 1 X . . . O . . . . . X O O . . O O . |
$$ | O O X X X O X X . X X O . . O O X X . |
$$ | O O O O O X O X X O O O O O . X . . . |
$$ | O O X X X X O O X X O X X X . X . . . |
$$ | . O O X . X O O O O O X . . . . . . . |
$$ | . O X . 2 . X . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

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The hane at move 67 seems overly ambitious. I would have extended safely, then played the nose tesuji.
( I'm not saying that it works, I'm just saying that I would have played it)

Click Here To Show Diagram Code

[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . O . . . , . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . O . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . X . . . . . . . . |
$$ | . . X . . 3 . . . . . X X . . . . . . |
$$ | . . . . . O . . . . . X O O . . O O . |
$$ | . . . . . O X X . X X O . . O O X X . |
$$ | . 2 O O O X O X X O O O O O . X . . . |
$$ | . 1 X X X X O O X X O X X X . X . . . |
$$ | . . . . . X O O O O O X . . . . . . . |
$$ | . . . . . . X . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

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Speaking of vital points...move 65 could have been this:

Click Here To Show Diagram Code

[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . O . . . , . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . O . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . 3 . . . . . . X . . . . . . . . |
$$ | . . . . . . . . . . . X X . . . . . . |
$$ | . . . 1 . O . . . . . X O O . . O O . |
$$ | . . . . 2 O X X . X X O . . O O X X . |
$$ | . . O O O X O X X O O O O O . X . . . |
$$ | . . X X X X O O X X O X X X . X . . . |
$$ | . . . . . X O O O O O X . . . . . . . |
$$ | . . . . . . X . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

_________________
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That hane is a known weakness in the white position. If white answers the C5 cut with D5, it becomes a Ko.
In this case, the white position was a bit stronger than usual and Black is a bit weak in the corner. In this psoition, you would want to be able to block at B2 instead of B6. Sneaking in a F7-G7 exchange would make the B2 block possible and capture the black stones cleanly (i think. In that case, your original hane move at B4 would have been a powerful tesuji.

In practice, it would probably be like this:

Click Here To Show Diagram Code

[go]$$
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . O . . . , . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . O . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . 5 . . . . . . X . . . . . . . . |
$$ | . . . . . . . . . . . X X . . . . . . |
$$ | . . . 3 . O . . . . . X O O . . O O . |
$$ | . . . . 4 O X X . X X O . . O O X X . |
$$ | . 2 O O O X O X X O O O O O . X . . . |
$$ | . 1 X X X X O O X X O X X X . X . . . |
$$ | . . . . . X O O O O O X . . . . . . . |
$$ | . . . . . . X . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

_________________
Help make L19 more organized. Make an index: https://lifein19x19.com/viewtopic.php?f=14&t=5207