The ball in its arch after it leaves the player's hands describes a curve similar to a parabola, the highest point of which intersects the imaginary locus. The distance of the shooter from the basket determines the point of intersection of the crest of the parabola with the line. The closer-in the shots are made, the farther down on the imaginary line will be the point of intersection. It is good pedagogy to teach the men to shoot for a direct looping hit into the basket. And this scheme of describing the imaginary line from a spot in the air is a means of stressing upon the players' minds the importance of shooting high.
Most players shoot too low and too short.
Should they overshoot, by correctly arching the shots, they will always have an extra chance for a goal on the rebound. He thought I was being a wise guy, but he should have let me try it - it couldn't have hurt my shooting.