30 years ago, I was teaching in a high school. There was a Judo club in that school. One day afternoon, I paid them a visit as a guest and watched their activities. One boy approached me, he said : ” Mr. Wong, I know you have practiced tai-ji for many years like playing with a water-melon, why don`t you joint our Judo club for better self-defense skills. I think Judo is much faster than tai-ji ! ” I said : ” Faster or slower should be expressed in terms of the number of operations not the speed you manage to apply for the action. For example you wanted to throw your partner as I saw just now, you needed to go through 3 operations : that is hand-work, foot-work then finally throw ! It seems not fast as your said, ” He replied : ” I try then I believe ! “. I stood up in front of him, he immediately grasped my T-shirt with both hands, before going to have the 2nd and 3rd operations, I simply grasped one of his palm, then turn my body slightly with the other hand pressed against his elbow （即反关节转身）. He shouted : ” Oh ! you almost fracture my elbow ! ” I replied : ” I used 2 operations only ! This movement is called tai-ji waving-hand ( 云手）. ”
Google+Tai-ji subdues Judo grasp by waving hand （云手）
