A special note: It can be very hard to determine exactly where a person's waist is and if the ball is being struck below the waist. Most important is that the paddle head is below the wrist bone when the paddle strikes the ball. If the whole paddlehead is below the wrist bone it forces the person to serve in an underhand motion. As you watch the video note that if the paddle head is not below the wrist the serve is illegal even if contact is below the waist.