The advantages of a tennis ball machine 

I have been playing tennis for over 25 years and have used a tennis ball machine for almost all of these 25 years. In order to excel at a sport you need constant repetition, which leads to highly responsive muscle memory.

This is especially true for tennis, and a tennis ball machine can help dramatically. The constant movement of going from forehand to backhand 100 times in a row can make a huge difference when you finally play a match. The 25 straight overheads you hit will be huge on that big point in a match.

I know tennis ball machines can be a little monotonous but if used sporadically, in between practices with a partner, it can not only drastically improve your game but it can greatly increase your endurance. You ever don't hit 40 or 50 balls in a point, unless you are on red clay in Spain, but you will with a tennis ball machine.

This gives you another huge advantage in tennis matches. As the point goes on, and your opponent tires, you are going to be fresh because of all those hours with your buddy...the ball machine.