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?
Does it deprive you of concentration? If so, either remove the cause, or if that is not possible strive to ignore it.
Once you have judged accurately your own reaction to conditions, study your opponents, to decide their temperaments. Like temperaments react similarly, and you may judge men of your own type by yourself. Opposite temperaments you must seek to compare with people whose reactions you know.
A person who can control his own mental processes stands an excellent chance...