This is an excerpt from Tennis Skills & Drills by Joey Rive & Scott Williams.
The value of the drop shot is its element of surprise. This shot is hit well by players such as Novak Djokovic, who has an aggressive baseline game that mixes power with finesse. Djokovic can use this shot as a way of enhancing his power game. Strategically, the drop shot can be used to bring an opponent to the net who doesn't like to volley or is uncomfortable at the net. The drop shot is used most effectively when the opponent is recovering after a shot and is stuck deep in the court. It is usually hit delicately. The success of the shot depends on the player's execution, the opponent's court position, and speed around the court.
The player can hit this shot in front of the body just over the net, at an angle, and inside out. The inside-out drop shot is derived from players using the inside-out forehand. It can be disguised if the player lines up as if about to hit an inside-out forehand, takes the normal backswing, and instead of hitting it normally, cuts the swing and places a ball inside out just over the net.
Preparation and Backswing: The forehand or backhand drop shot requires either the Eastern or Continental grip. The player should be in front of the baseline when playing this shot. To surprise the opponent, the player's stance should be the same as for the regular groundstroke (figure 8.7). The player takes the racket quickly back, slightly higher than the level of the oncoming ball, with a quarter turn and a shorter backswing, in a manner similar to that for the block shot.
Forward Swing and Contact: The racket face is open and travels down (see figure 8.8) and across the ball for underspin, from low to high for backspin, or from right to left for a right-handed player and left to right for a left-handed player for side spin. Which spin to use depends on what type of drop shot the player is trying to hit. A great drop shot can be played three ways. With underspin, it goes over the net and softly bounces three to five times on the service box. With backspin, it goes over the net, stops or rolls back to the net, or in some cases, bounces on the opponent's side and comes back over the net. With sidespin, it bounces on the opponent's side of the court and goes off the court after that bounce. The contact point needs to be in a position that is comfortable for the player. The drop shot can be hit from all three contact points and strike zones but is best hit from the low- to midlevel strike zone.
Follow-Through: The follow-through is short and ends slightly in front of the body. The face of the racket is open at the end of the movement (see figure 8.9). The body is balanced.