(No. 162: May 31, 1999)
Elementary level: Answer
Black 1 is the vital point to get a Ko.
Elementary level: Wrong Answer
Black 1 allows White to play on the vital point 4
and loses the capturing race.
Intermediate level: Answer
The series of Black's moves 1 to 9 is the Tesuji.
After White 12, to the next diagram.
Intermediate level: Answer(continued)
Black wins the capturing race, with 13 and 15.
Intermediate level: Variation
If White 2, Black wins the race with 3 to 5.
If White 2 at 5, Black wins with 2.
Intermediate level: Wrong Answer
Black 5 allows White to get a Ko with 6 and 8.