Bend It Like Beckham

A tennis ball doesn't go directly where you hit it. It goes where you hit it plus or minus whatever the invisible forces of nature bring to bear. Gravity is the force that is most apparent (I've never hit a ball that didn't come down) and a ball hit into the net is the penalty you will pay for underestimating it!

A ball traveling 78 feet (the distance from one baseline to the other) is also affected by atmospheric pressure and density. Ball manufacturers actually make high altitude balls that are a bit bigger, 6% to be precise, to counteract those two variables when matches are played at 3,500 feet or more above sea level.

The other forces that determine ball flight, and therefore accuracy, are racket face angle, swing path and collision speed. Those three things determine how much spin and what type of spin will be produced and at what speed. 99.9% of tennis shots have spin on them - some purposeful, some inadvertent. The more skilled the player, the less shots are spun inadvertently.

Topspin/overspin, underspin/backspin, side spin/hook/ fade spin are the types of spins high level players employ in nearly every point played.

Topspin/overspin is the meat and potatoes of most elite level players' menu of skills. Contrary to its name, it has nothing to do with the strings touching the top of, or rolling the racket face, over the ball.

To produce topspin effectively, a vertical racket face traveling on an upward (low to high) swing plane should actively brush up the back of the ball to create lift (remember the gravity and net idea?) and impart forward spin, which has the effect of drawing the ball downward after that initial lift (up over the net good - back down into the court good).

 When you hear a TV announcer mention coming over the ball, or getting on top of the ball, please don't let that image into your mind. Be sure you brush it up to bend it in like Beckham!