PLAYERS should constantly study the “angles” of the court. By “angles” I mean the lines of direction the ball nay take in being returned by your opponent from a given point to your court. Knowing the angles reduces the ground you have to cover. Take the center of the court for the dividing line in choosing your points of defense. The ingles of the court change according to the position of your opponent.
If a ball is driven on the return from the center of the court, the best position for your defense is also the center.
On forehand cross court shots, where your opponent is out of court on your left, your position would be more to the left side of your court.
On a back hand return from an opponent who is far to the right your best position is also to the right of your court. This applies when playing net against your opponent. If on a return from an opponent well to the right you volley to the left of his court from a position on the right of your own court the angle of your volley favors you and you are less likely to be passed, even if he can make a return. Therefore it is a mistake in such a case to take a center line position instead of one to the right of the center To put it briefly, opponent to your right, go to the right for defense; opponent to your left go to the left for defense .
Of course in addition to the angles one must also know the speed, height, and drop of the ball. But those points are considered elsewhere.
By the diagrams of the court shown herewith the player can see for himself the “angles” of the shots. In these diagrams A shows the point from which your opponent is returning the ball. Divide the line of the two widest possible returns that will not land out of court equally and it will tell you the line on which to stand.