The strike must have a short interval of 4 to 8 inches, just before the ball is struck, over which the orientation of the racquet face does not change. This is discussed in Strike. In the figure below, we illustrate an exercise to aid in the development of the feeling you experience while executing this motion.

The player holds the racquet in the usual grip (western in the illustration) and presses against the coach's hand as shown. The coach slowly yields to the pressure to give the feeling of moving the racquet in a straight line without rotating it.