What are the technical essentials of tennis serve?

(1) Tennis grip, European or Oriental backhand grip.

(2) Ready to relax, stand sideways near the midfield mark outside the end line (singles), with the left shoulder facing the left net post and the right net post. Your feet are about the same width apart, and your left foot is about 45 inches from the finish line. Your right foot is approximately parallel to the finish line, and your center of gravity is on your left foot. Hold the ball in your left hand, gently hold the racket around your waist, and the racket head points forward. Breathe evenly and concentrate.

(3) Throw the ball out and swing it back. Throw the ball out and swing it back. The ball holder gently holds the ball with his thumb, forefinger and middle finger, palm up. When the racket is pulled down and backward, the player will reach the right leg at the same time. Then, when the racket swings in an arc from the back to the top of the head, and the body rotates, bends its knees and spreads its shoulders, the ball holder gently lifts it in front of the left foot until it reaches the top of the head. The throwing action should be coordinated and smooth. Send the ball to the highest point and throw it into the air from your fingers. At this time, the right elbow is spread back about shoulder height, the racket head points to the sky, the left waist and hip are arched, and the body center of gravity moves to the right foot first with the ball throwing, and then moves forward smoothly. At this time, the shoulders are at right angles to the net.

(4) hit the ball. When the left hand throws the ball, the racket continues to swing upward. At this time, the elbow joint of the hand holding the racket is relaxed, which can make the body rotate forward, and the right shoulder automatically makes the arm make a perfect circle (be careful not to ask the racket to scratch the back). When the ball falls to the hitting point, swing it quickly and push your left foot upward, so that your arms and body can be fully extended. When your body stretches forward to hit the ball, your shoulders and arms have turned around and your shoulders are parallel to the net. When hitting the ball with a swing, the wrist holding the lever drives the forearm to produce a "whipping" action, which is the key action of serving power and the sum of other forces such as moving the center of gravity forward, kicking, turning and swinging.

(5) After the follow-up action ball is served, the body leans towards the field to maintain a continuous and complete follow-up action extending forward and upward. The racket swings to the left side of the body (the American rotary serve racket swings to the right side of the body), the center of gravity moves forward, and it follows up completely naturally to keep the body balanced.