Andrws Pitchfork is a "combat efficiency trend channel" that an internal trend line was added.
The price development is based on the upper and lower trend line. During the correction / recovery phases bounces the course of the internal trend line or it finds a Kiss back motion at this "center line" instead.
The following figure shows a representation of the shematische Andrews Pitchfork, which is bounded by a lower and upper trend line and an internal trend line contains.
The Dow Jones Industrial moved about two years in a Pitchfork. This, while not particularly "elegant", but it recognizes the fundamental principle.