In high-level tennis, even when a tennis ball is hurtling toward the pro at 80 to 130 miles an hour, to him (or her) the ball appears much slower. Not only that, but the ball can seem as big as a basketball! How does this strange phenomenon happen? Can the same happen for you? Yes it can, and it will bring more benefits to your game than you think.
 
With time, determination, and massive repetition, you can accomplish the uncanny feat of slowing the ball down (relative, of course, to your playing level). The trick is to allow your unconscious mind to see the ball at different speeds and trajectories over and over and over again. To train your brain in this way, you must put yourself through a host of drills for weeks, months and years.
 
Recently I was reading an online discussion about how to slow down the ball in tennis. Two posts in particular gave some excellent advice:
 

"If you want to go about this systematically use a ball machine. Every time you fill up the hopper, turn up the speed a little. It's amazing how even over the course of an hour the eyes/mind/body reacts. Balls that seemed fast at the start now are slower than routine. Keep it up over a period of weeks and the difference is amazing. Keep it up for years at 3,000 balls a day and you have Agassi's boyhood training mechanism under his crazy dad's instruction."
 
"Simply put, the more you are exposed to fast-paced shots the better. Your eyes and body will naturally get used to the speed and you'll be able to see it in "slow motion." If there is one thing amazing about living things, it's the ability to adapt. Use that to your advantage! As for what to do, you can use a ball machine and set it to the fastest pace and shorten the interval between each feed. If you don't have access to a ball machine, find someone who can consistently hit fast-paced shots. If you can't find anyone who can do that, get 2 buddies and get a rally going with 2 balls at once."