Answer to Q99

Answers

(No. 99: Mar. 16, 1998)

Elementary level: Answer

Black 1 is the vital point.
After White 2, Black 3 gets a Seki and lives.

Elementary level: Wrong Answer 1

Black 1 allows White to play 2 and get a Ko.
(This is a ten-thousand-year Ko.)

Elementary level: Wrong Answer 2

Black 1 is wrong. After White 2,
Black has no choice but to get a Ko with 3.

Intermediate level: Answer

Black 1, attacking from outside,
is crucial to destroy White's eye shape.
There is no way for White to live.
If White 2 at 5, Black 4 kills White.
This may look easy as a problem,
but I have seen an amateur Dan-holder miss it in a real game.

Intermediate level: Wrong Answer 1

Black 1 fails. It allows White to get two eyes with 2.

Intermediate level: Wrong Answer 2

Black 1 also fails. White lives with 2 to 10.