|The middle game (4) Oi-otoshi|
|*||The fighting technique: oi-otoshi|
|Dia. 1. If Black plays on the point marked in red, the four white stones will be in atari, but if White connects in order to escape atari, something terrible happens.|
|Dia. 2. The instant that White connects to avoid atari, he finds that his stones are still in atari. This sort of position or capturing technique is called oi-otoshi.|
|*||How to set up oi-otoshi|
|Dia. 3. Please look at how one sets up oi-otoshi.
|*||The crane's nest|
|Dia. 4. This is an interesting shape known as 'the crane's nest'.|
|Dia. 4||Dia. 5|
|Dia. 5. If Black plays at 1, White links up with 2, and Black can't continue his attack.|
|Dia. 6. Black 1 is the vital point.
White can capture Black 1 by playing 2 and 4, but when Black plays 5, the five white stones are in atari. Even if White connects (at 1), his stones remain in atari, so they are captured. This is a kind of oi-otoshi.