This exercise is the first progression in learning the X4 smash technique. Before using a racket, the player begins by isolating the wrist movement needed to make the ball travel sharply downwards towards the ground.
The objective is to achieve the highest possible contact point, with the dominant arm almost fully extended, then perform a vertical wrist movement to drive the ball downwards.
This first progression helps the player understand how the wrist movement affects the ball’s trajectory and the height of its bounce.