Master Chen Zhonghua has demonstrated numerous times of having a fixed point (dot) for rotation in his action. Recently, I start to understand the pair of contacting points which can be used to create a stick/lever. I have been able to rotate an opponent using a dot in the middle of the stick. Today, I realize this dot can, in fact, be in space, and not necessarily in the opponent's body. It depends on how I contact the opponent, e.g. which body parts I use to create the stick. This kind of rotation is vertical, and can take the bottom support out from the opponent.
Update on June 18, 2016:
Today, related to this idea, I found myself using a stick created by my opponent on my body trying to do a move on me. The move he was trying was with his right arm across my chest and his right leg behind my left leg to flip me backwards. Between the contact point on my chest and the contact point behind my left thigh, a stick was formed. If I considered this stick with a third point on his body where he powered up, a triangle (a plane) was formed. I was able to rotate the dot in the middle of the stick between the two contact points, and flipped him forward.
Update on June 20, 2016:
I discovered there was yet another triangle. With the stick being one side of the triangle, I can have a point of another triangle at my waist/dantian. When I rotate my waist, I rotate the stick. This should be the concept of a fork as documented in my notes back in 2010:
What's the dot?