"When you are in a matching situation with your opponent, there are three circles of offensive and defensive domains or territories. These circles are large circle (Chang Ju, i.e., long range), middle circle (Zhon Ju, i.e., middle range), and short circle (Duan Ju, i.e., short range). These circles are also called rings. In a battle, you should not stay in the same rign, which allows your opponent to set up a strategy against you easily. Your rights should be variable, random and confusing to your opponent. Not only just the size of the rings, but also the height of defensive and offensive actions should vary as well. When this happens, you will generate more confusion for your opponent and this will allow you to execute your techniques effectively and efficiently."
- Yang, Yu (Ban-Hou) 1837-1892
Translated by Yang, Jiwng-Ming, Tai Chi Secrets of the Yang Style, p. 24
Most people doing Tai Chi will be concerned about the following three circles. The first circle is the area in which you are standing. Where are you rooted? How is your footing? Are you stable, balanced, and in control? Are you safe? It includes the spherical area your arms and legs can extend to while keeping at least one foot rooted. The second circle is the area into which you are stepping next. Is it safe to step? Will you be able to stay stable, balanced, and in control as you step into one of the eight directions? It includes the spherical area your arms and legs can extend to as you step and move in a new direction. Will the first circle support your full weight on one leg as you move into the second circle? The third circle is the area into which you can walk, move freely, and move around in safely. It may be the whole area of a park, the dojo or kwoon, your backyard, your back porch, or as far away as you can walk.