RTG Problem 17 / Attempts

Black kills  

JoelR: ... and a picks up.
limits White's eyespace, and forces . threatens to cut at . If at a, then at , and Black has more liberties.

Approach Ko  

Dieter: If here, starts an approach ko ( at a), which is favorable for Black.

Seki  

If here instead, makes it a seki.

Kill  

would be a mistake. Black throws in and wins the capturing race by one liberty.

Failure  

If Black wants to avoid the approach ko, he could make the placement of but is as vital a point:

Seki again  

White lives with seki. She can also play at , if a direct ko is what she wants.

Dieter's solution  

... but in my opinion, this is the solution. It's almost the same as the earlier approach ko solution, but Black can have White play one more ko-threat. In other words, will count as a ko-threat.

Order of moves  

The order of play can be reversed.

Caution  

If and , is essential.

Miai  

In this variation, a and b are miai to kill.

Black kills  

Bill: I think this is the right third move.

There are several variations.