RTG Problem 84 / Solution

The one-two point  

Play the 1-2 point closest to the stones cut off.

The wrong one-two point  

It is not true that any 1-2 point works. White 1 plays at the wrong 1-2 point and loses the capturing race instead.

The hane leads to ko (9 takes ko at 1)  

The hane leads to ko.

Failure  

If is played as in this diagram instead, white loses the capturing race.

Black cannot avoid ko  

If tries to avoid ko, then is the tesuji that wins the capturing race unconditionally.