Lesson 109: Brilliant Self-Atari (2)

By Nam Chi-hyung

Just as there is an instinctive dislike against an empty triangle shape; putting the friendly stones in atari is naturally abhorred by players. Therefore, maybe the main difficulty of finding the answer of the following problems is not your reading skill, but your prejudice about the shapes.

Diagram 1

You have to save either the white stones in the corner or the two stones on the left. Since the two ▲-marked white stones don’t have many liberties, White needs a very smart move.

Diagram 2

White 1 may be a natural move, but White 3 will be pretty hard to find, even if you already know what to look for. White 3 doesn’t directly help either the three stones on the right or the two stones on the left, but only adds another weak stone. However, it is a really brilliant move which puts Black in a dilemma. If Black tries to capture any of the white stones with either A or B, White will capture either the three black stones on the right or the two black stones on the left with C.

Diagram 3

White’s goal is to kill the entire black group on the side. If White just plays A, Black will save the group on the right with B.

Diagram 4

White 1 and 3 are to prevent Black from playing A. The most important move is White 5, which puts the two white stones in atari. It is the only way to deter Black’s playing A. Then, what should be White’s next move after Black’s capturing with 6? Although not shown in the diagram, White 7 should be at 3, which is still blocking Black from playing A. As you may have already noticed, White’s moves from 3 to 7 put not only himself but also Black’s playing A into atari.

Diagram 5

This is a very interesting situation. It seems to be a dual-life because neither player can play A nor B. But stop! It is true that Black cannot play either position, but is the same true for White?

Diagram 6

What if White plays B in Dia.5? Then Black cannot help but capture the three white stones with 2, and then White will take Black 2 with 3. Now the situation is totally changed from the one in the last diagram, since Black cannot turn the situation to a dual-life as before by playing A. Black’s playing A would just result in the death of his own group, which is a flower-five. On the contrary, White can always play A and start a ko as you can see.

Let’s go back to the original situation in Dia.5. It ends as a dual-life if that is what White wants. However, White can also turn the situation into a ko by means of putting himself in self-atari. This means that White can choose the most favorable timing for him to start the ko in this shape. It would be a time-bomb for Black!

The writer is a baduk professor at Myongji University and a professional player of the game.

chihyung@mju.ac.kr