Solution
The solution is . Black is captured cleanly without ko.
If connects, then wins the capturing race by one move.
For here, results in a snapback.
Failure
The atari at here allows to start an approach ko. Although this ko is favourable to White, but it is still a ko and not unconditional life, so we consider it a failure for White.
The throw-in at is worse. After , it is either seki or direct ko.
Referenced byCapturingRaceExer...