Probably the most useful part of our tennis game is our wrist. Every single ball we hit we will use our wrist for control. But how much wrist should we be using? Well that entirely depends upon the kind of ball. But when the ball is right in our strike zone we are looking for about a 3/4 turn of the wrist.
First, notice how the wrist begins to move before contact with the ball. It is very important that when we contact the ball, the blade should already be out in front of the handle.
Next, as Andy Murray flicks his wrist, his wrist will come over the top of the ball. Thus giving us complete topsin. We want our palm to go over the ball so that we are not opening the racquet face.
Last, he makes about a 3/4 turn of the wrist and follow through with this hand on top of his shoulder.
Remember, wrist will always give you complete control of your shots. You'll never want to use your arm or hand for the control, only wrist.