is considered a failure in this problem. After , if White saves the two stones at a, then it is gote. Nothing more than an itch for Black.
Bill: - is fairly large, about 8.7 points.
connects at .
is almost as large, about 8.4 (8.5 points when White is komaster). So White will often be able to play here with sente.
Later - is sente, and even later - is sente.
The count in this end position is -1 for the captured stone. White at would forestall 2 points and then create a ko to capture first in sente. So is a 2 1/3 sente. White at would forestall 3 points (and no more if Black is komaster), so is a 3 point sente