British Go Journal No. 60. September 1983. Page 26.
This article is devoted not so much to a particular shape, but to a bad habit which many players suffer from.
Your opponent has a cutting stone, you have two ways to play atari against it, and the bad habit is to assume automatically that one of those ataris is correct
Dia 1 ||
Dia 2 |
Dia 1 shows a well known joseki. Black cuts at 1, white 2 is then correct. Black has to extend his cutting stone in any case, so White gets sente to play 4.
Dia 2 shows the thoughtless atari in action. Now when Black plays 2, White has a weakness, and if he protects it by connecting at 3, Black can attack his group on a large scale with 4. In Dia 2 White has wasted almost a whole stone.
Dia 3 |
Dia 3 shows another example. White decides that he cannot kill the black cutting stone, and may feel tempted to play the atari at A. But Black is going to connect at 2 more or less whatever happens, so it is better to choose some other play, like white 1, which is more use than A for developing the white group.
Dia 4 |
Dia 4 is taken from the game between Francis Roads and John Rickard, which is discussed on pages 18 and 19 of this journal. In the actual game, John played atari at A and B, forcing White to capture at C, before he continued at 1. Had he omitted the thoughtless ataris and played 1 immediately, as shown here, it would have been impossible for White to capture at 2, due to the tesuji at 3. In the game variation, White was able to handle his problems one at a time. The correct variation confronts him with both of them at once.