Endgame Problem 9 / Solution

Solution  

is the solution, not a.

Solution  

What is so painful for Black is that is practically a sente move during the endgame phase. After , then White can tenuki, so White has reduced Black's territory in sente.

Variation  

does not work either. Black loses even more this way.

Failure  

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.

The more formal analysis

Almost sente  

Bill: - is fairly large, about 8.7 points.

Large gote  

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.