This shape is an empty triangle, empty referring to the unoccupied point at . Most people like to say that the empty triangle is bad, being inefficient and prone to shortage of liberties. The empty triangle is also sometimes called the devil's shape (onigatachi), because it brings to mind the long nose of one kind of Japanese demon.
is a hane on the second line. Black may fear what happens if he blocks. In the left diagram he creates an empty triangle. Things get worse with , wrapping around it and reducing the liberties to 3. In the right diagram, forces to connect and creates good shape with three in a row.
- Guo Juan's AudioGoLessons has three audiolectures on empty triangles.
- Empty Triangle is also the name of a Go comic strip (Site with internal error).
 Some imagination is called for here