Tennis psychology is nothing more than understanding the workings of your opponent's mind, and gauging the effect of your own game on his mental viewpoint, and understanding the mental effects resulting from the various external causes on your own mind. You cannot be a successful psychologist of others without first understanding your own mental processes, you must study the effect on yourself of the same happening under different circumstances. You react differently in different moods and under different conditions. You must realize the effect on your game of the resulting irritation, pleasure, confusion, or whatever form your reaction takes. Does it increase your efficiency? If so, strive for it, but never give it to your opponent