For tennis ball machines to shoot balls with perfect accuracy and at nearly 100 miles per hour, it takes a series of carefully calibrated parts working together. Here's what it looks like inside.

Whether you're a beginner looking to improve your backhand or a seasoned player working on your serve, a tennis ball machine can be the game-changer you've been waiting for. Offering the freedom ...

But what if someone took the greatest shots from the top players and made one perfect tennis machine? The stars on the ATP Tour were tasked with just that, choosing who had the best shots to see ...