All sports are not same as each other. Some of them are very easy, and rests of them are difficult. As me, Tennis is difficult game, and to become a good tennis player is extremely difficult. Generally, Player needs to follow all rules of tennis to be a good tennis player, but as me, it is not enough. In order to become a good tennis player, person needs to follow a procedure.
Firstly, person needs to concentrate while playing. Especially in tennis, player must concentrate on ball and opposite player too. Instead of looking at audience, player has to concentrate on the game. Also, concentration can help player to make good judgement. As monica sales, a great tennis champion, concentration always helped her to make good decision while playing. Also, she can play without any stress because of concentration on the game.
Secondly, player must do exercises every day. A good tennis player needs strong arms and legs.
Exercises can give enough strength to body. Not only strong arms and legs, but player needs quick movement too. For instance, pit samprase, one of the best player of tennis, exercises everyday. As him, he cann't move very quickly from one end of tennis court to other end without doing exercises everyday. Exercises can make body flexible and smooth too. If player has enough strong and flexible body, he/she can play well.
Not only concentration and exercises, but player needs more and more practice too. Somebody said, "practice makes man perfect." It is true. Andre agassi, Pit sampras, martina hingis, monica sales, etc play tennis everyday just for practice. Martina was only thirteen when she started to play, and even today she practise everyday. As her, practise helps her to play better and better. Even before each game in tennis, players do warm-up practise. It helps them to play well. Each tennis player must practice everyday.
Concentration, exercises and practise are three keys to become a good tennis player. If anybody will use all these keys, he/she will be able to play tennis well.