Basics 2--Chi Sao

It has been said that "without Chi Sao, there is no Wing Chun" and I believe this to be true. Chi Sao, or "sticky hands" is unique to Wing Chun. Other arts have some sort of hand play but none (as far as I know), have the interactive two hand play that Wing Chun has. Wing Chun uses both hands working simultaneously. Usually, a student starts learning Single Chi Sao, which is sticking with one hand and progresses to full Chi Sao. I will get more into single later. Chi Sao normally teaches a student to be sensitive to very small movements of the opponent. He can react to exactly what is going on at the time. Some Wing Chun people call Chi Sao "contact reflexes", which is actually a very good name for it. Basically, what happens in Chi Sao is "the forearms, hands, and fingers are very sensitive to movement and can be taught control in a very subtle way." The purpose then is to show a learning link between forms and fighting and this is easily accomplished after learning the basics of rolling hands and hand changes (two types of changing the hands in rolling hands).
After the basic skills of Poon Sao (rolling arms) has been learned and mastered, the student can progress to the basic shapes of Chi Sao, i.e, Bong, Tan, and Fuk Sao. Then the student can progress into full Chi Sao. The student should learn the basic push hand changes and then free hands. The idea is that when a hand is pushed off the center, it has to return to the center as smoothly and fast as possible. These techniques can be taught from rolling arms on individual hands at first but should be brought together as soon as he/she is familiar with rolling arms. All of this will be discussed later in detail. These are just the basics. Please feel free to post if you want to add to or discuss in any way (even to disagree)!