Answers

(No. 163: Jun. 7, 1999)

Elementary level: Answer

Black 1 is the vital point. After White 2,
Black plays 3 and 5 to win the race. White dies.

Elementary level: Wrong Answer

Black 1 first allows White to capture Black with 2 and 4.

Intermediate level: Answer

The combination of Black's moves 1 to 5 is crucial.
Black gets a Ko with the moves to 13.
(This is the same shape as the problem No.162 elementary level.)

:

connects over

Intermediate level: Reference Diagram

If White 6, Black kills White with 7 to 11.