As players hit with more power and more top spin the drop shot has become increasingly effective as a surprise variation.
Use this when you have forced your opponent back behind the baseline with a series of deep and powerful shots.
Then surprise them with a shot that just goes over the net with some backspin to kill the bounce.
Ideally the ball that is coming to you should not be too low and will also have a little bit of pace on it - it is very difficult to hit a drop shot of a very slow moving ball.
Disguise is vital. You want your opponent to be on their heels expecting a deep powerful shot from you.
To do this you need to move up to the ball and prepare as if you were going to hit a topspin drive.
You need to set up with a big back swing and shape to hit a topspin shot.
Then at the last second change the shot.
Shorten your back swing right down and move your racquet head to the ball with a slightly open racquet face.
Soften your grip on the racquet and as you hit the shot try to feel your racquet face cushion down the back and underneath the ball.
This will take the pace off the shot and will also generate some backspin killing the bounce.
Hopefully your drop shot will be so good that your opponent will not reach it at all.
Often though they just manage to scrape it back.
Because of this you need to follow your drop shot in to the net a little.
This way you are in position to kill off any weak return that comes your way.