Problem at it appears in the book Weiqi Rapid Drill 800 Problems problem 4.
Why not this . make miai of and .
Perhaps its just go blindness on my part.
Logan?: Black receives two extra ko threats by following the sequence outlined in the book. As notated in the second diagram ("Book Solution") Black can press at 'a' for the first ko threat and then at 'b' for the second.
Bill: Sometimes one play is better, sometimes the other. (Both are the same size.)
Assuming that the rest of the board is settled, is 1 point worse than the book solution. (White gets the points.)
Assuming that the rest of the board is settled, is better than the book solution. After gets the last play, capturing the White stone. (4 and 5 are miai.)
If Black plays the book solution, gets the last play and saves the White stone, which is 1 point worse for Black.