First of all I understand pronation to be as follows: If you held your right arm and hand up to contact the ball with the leading edge of the racquet, the right thumb and forearm would roll so that the thumb rotates downward, forearm to the left and your wrist moves to the left such that you can read your wristwatch. This happens automatically as you swing forward with the leading edge of the racquet and your forearm, wrist and hand pronate as it nears the contact point. My pro once held up a tennis ball affixed to the top of a stick that rotated around a fixed axis -- it would spin clockwise or counterclockwise depending on whether you strike the left or right side of the ball. It seems like to make it spin to the right (topspin or kick serve?) you are not pronating. Is this right? If not, how can you make the ball rotate to the right if you pronate which seems like you are striking the left side of the ball. If your wrist at the top (palm is facing the net), aren't you pronating when you move your wrist to the left and supinating if you are moving your wrist to the right side? This has always confused me. Also, my question is whether you are pronating on a flat, topspin or kick serve or whether you are supinating depending on the type of serve. And lastly, should I be able to pronate (wrist to the left and thumb down) on every type of serve. Thanks in advance.