September 28, 2009
Black 1 is the vital point.
If White 2, Black kills White with 3 to 9.
If White 2 at 9, Black 3 kills White.
Black 1 and 3 are crucial.
If White 4 and 6, the result is a Ko with the moves to Black 7 to 11. (one-move-approach Ko for White).
