Solution
After , Black lives as a twisted four. Now a and b are miai, c and d are also miai for life.
Failure 1
Black dies by bulky five.
Failure 2
Playing at looks good, but will capture the marked stone. However, has to be careful not to play at a or b.
Failure 3
is the vital point here.
Failure 4
is probably the weakest move among the failure diagrams.
Referenced byBeginnerExercise69