Wow! I didn't expect black to start the ko in the top left so early.
Black has more local ko threats and it looks like white only has a few in the top right, which will probably be ignored, but I thought the fight was ok for black without resorting to a ko and that white's running group was a bit heavy.
It's a two stage ko, which seems annoying for black, and if white wins it he can also eat that five stone clump to help the center group. So I can't help feeling that starting the ko makes white more a bit more flexible in the top left, though I'm sure Yamashita has already calculated this quite carefully.
What do other people think about this position?
EDIT: Here's the position for anyone who can't watch online or is reading this later:
$$W Black starts the ko.

takes the ko back.
$$ +---------------------------------------+
$$ | . O . . . . . . . . . . . . X . . . . |
$$ | O . O X X . . O . . . . . O X O O . . |
$$ | 2 O X X O X . X O O . . . O X X O . . |
$$ | 3 X O O . X . O . O . . . . . X O . . |
$$ | X X X O . . . O . O . . . . . . O O . |
$$ | . X O O . X . . O X O . . X . X X X . |
$$ | . . X O . 4 1 . . X X . . . . . . . . |
$$ | . . X O . 5 . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . O . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+
- Click Here To Show Diagram Code
[go]$$W Black starts the ko.
takes the ko back.
$$ +---------------------------------------+
$$ | . O . . . . . . . . . . . . X . . . . |
$$ | O . O X X . . O . . . . . O X O O . . |
$$ | 2 O X X O X . X O O . . . O X X O . . |
$$ | 3 X O O . X . O . O . . . . . X O . . |
$$ | X X X O . . . O . O . . . . . . O O . |
$$ | . X O O . X . . O X O . . X . X X X . |
$$ | . . X O . 4 1 . . X X . . . . . . . . |
$$ | . . X O . 5 . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . O . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]
While I was writing this, two more moves were played...
$$W Yamashita makes white heavy.
$$ +---------------------------------------+
$$ | . O . . . . . . . . . . . . X . . . . |
$$ | O . O X X . . O . . . . . O X O O . . |
$$ | B O X X O X . X O O . . . O X X O . . |
$$ | . X O O . X . O . O . . . . . X O . . |
$$ | X X X O . . . O . O . . . . . 1 O O . |
$$ | . X O O . X . . O X O . . X . X X X . |
$$ | . . X O . X O . . X X . . . . . . . . |
$$ | . . X O . O . . . . . . . . . . . . . |
$$ | . . X . . 2 . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . O . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+
- Click Here To Show Diagram Code
[go]$$W Yamashita makes white heavy.
$$ +---------------------------------------+
$$ | . O . . . . . . . . . . . . X . . . . |
$$ | O . O X X . . O . . . . . O X O O . . |
$$ | B O X X O X . X O O . . . O X X O . . |
$$ | . X O O . X . O . O . . . . . X O . . |
$$ | X X X O . . . O . O . . . . . 1 O O . |
$$ | . X O O . X . . O X O . . X . X X X . |
$$ | . . X O . X O . . X X . . . . . . . . |
$$ | . . X O . O . . . . . . . . . . . . . |
$$ | . . X . . 2 . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . O . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]
What an exciting final game!
