Question: How would I hit a backspin serve?
Answer: Use a normal stance and a Continental grip. Toss the ball roughly as high as your chin. Without a wind-up, bring the racquet straight back around navel high. As you swing forward, bend your knees to accentuate your brushing down the back of the ball. Swing straight toward your target. The swing is similar to a drop shot, but instead of trying to take pace off the ball, you have to generate enough power to send the ball more than 40 feet, which still keeping it soft and short enough to act like a drop shot. It's a difficult serve to use effectively.

