Question: How would I hit a underhand sidespin serve?
Answer: Use a Continental grip and a normal stance. Toss the ball roughly as high as your chin. Without a wind-up, lift the racquet roughly shoulder high, well out to your right side. Once the ball has fallen below your knees, cut across the back and bottom of the ball sharply from your right to your left, with your body aligned so that the direction of that swing will be diagonally forward. The racquet face will describe a shallow "U" in front of you, meeting the ball at the bottom of the "U."
