Monday, March 12, 2012


How important is technique in tennis? How important are mechanics? The two are not quite the same thing, but both are important. I don't, however, think that either is as fundamental as one other skill, namely hitting the ball cleanly, whether with spin or without as you choose in various contexts.

I think of technique as a broad term for how you do something like swing a tennis racquet, golf club, baseball bat, or play the piano, drive a car or perform any task. I'm not a linguist, but I think the term comes from the Greek word technĂȘ.

Mechanics, on the other hand, refers to Newtonian physics which deals with forces acting on the body and forces generated by the muscles of the body. When we talk mechanics, we're talking about how efficient your technique is in producing racquet speed, primarily.

So people can have better or worse technique and better or worse mechanics. The two are interrelated but are not exactly the same thing.

Players with good mechanics use their neuro-muscular system efficiently. They generate the most racquet speed with the least effort. So how important is this to playing tennis well?

For the serve, it's darn important. Given that the timing of hitting the ball is fairly simple, mechanics almost totally determine the quality of a serve. Even with a fairly high toss, the ball is moving pretty slowly and very predictably prior to and at impact. So the eye-hand coordination needed to hit a serve well can be accomplished by most people over time.

Not so with forehands and backhands. If a coach feeds a ball to a player, then the eye-hand skill necessary to hit a ball well is not so different from a serve. If a coach stands in front of a player and hand-feeds the ball for forehands and backhands, then the eye-hand skill needed is probably less than for a serve. So this closed environment is good for isolating work on mechanics. But the world of tennis is very, very different from that hand-fed world.

Another skill is needed before the mechanics and technique will be of use. That skill is a perceptual skill. The player must learn to track and intercept a moving ball with a tennis racquet whose hitting area is roughly 45 cm from the player's hand. The hitting area of the racquet may be as large as 135 sq cm, but in reality the "sweet spot" of the racquet is much, much smaller than that. I don't have data on this, but if you can't hit the ball in an area of 20 sq cm or less I don't think you'll be much of a tennis player.

This 20 sq cm area must intercept the ball somewhere in front of, and off to the side of, your body, too, to be effective for most shots. Tennis balls don't arrive reliably and predictably in this "strike zone" in front of and to the side of a player's body. The player must move in response to the speed, depth, height and spin of the incoming ball to place the strike zone when and where it needs to be for the player to hit a solid forehand or backhand.

After this movement, the player still must time his or her stroke to get the 20 sq cm or less racquet surface area and ball to meet in that strike zone. The hitting surface must be angled properly to hit whatever shot the player intends.

All of this perceiving, moving, timing and aligning takes place in under two seconds for almost all levels of play. It takes about one second at the top level of play. Since human reaction time is at least 0.2 seconds, some of this movement needs to take place before the opponent even hits the ball.

Because of all this, I think it's safe to say that perceptual skills are prior in every way to mechanics and technique. Without the ability to judge the velocity and spin of the incoming ball, a player simply cannot use his or her wonderful mechanical technique to hit forehands and backhands.

This has become clear to me as I've experimented under different visual conditions. I'm blessed with poor uncorrected vision. Without glasses I see worse than 20-400. Thankfully with glasses and contacts, my vision is corrected to 20-20 or better. My poor vision, and aging eyes (I'm nearly 50 yrs old) allow me to experiment with sub-par vision and tennis. I play my best wearing contact lenses in bright sunlight. I play better with contact lenses than with glasses under all lighting conditions. I can hardly play at all without correction, though I can hit the ball a bit.

My technique and mechanics do not change as I go from contacts to glasses, from sunlight to artificial light, to no correction at all. But my skill level changes dramatically. I go from capable of hitting with anyone in the world, to not being able to sustain a rally from baseline to baseline above about 40 mph ball speeds as I remove my contacts and glasses. That's quite a drop off.

I'm not saying that technique and mechanics don't matter. Far from it. If you want to hit a 120 mph serve, your mechanics had better be good. If you want to crack a sitter forehand over 100 mph, your mechanics had better be good.

But if you want to play high level tennis, sustain rallies with ball speeds over 70 mph, then hitting the ball cleanly is much more important than efficiently generating racquet speeds. I've seen little girls with suspect mechanics rally upwards of 80 mph simply by hitting the ball solidly over and over again.

Friday, March 09, 2012

To Push

Here's how The Free Dictionary defines the verb "push":
push  (psh)
v. pushed, push·ing, push·es
1. To apply pressure against for the purpose of moving: push a shopping cart through the aisles of a market.
In tennis, "to push" is to simply put the ball in play with the goal of waiting for your opponent to miss. The term is a pejorative. Nobody wants to be called a pusher.

My question is, do we tennis coaches encourage "pushing" when we instruct a player to "get your weight into the shot"?

I think the answer is unequivocally yes. When a human pushes something, a shopping cart in the definition above, a door, a car, the human puts his or her weight into the task. The person exerts pressure by the arms and by body weight. So putting your weight into something is fundamental to pushing.

Swinging, on the other hand, which is what a tennis player should do in order to move the racquet quickly to hit a ball hard, does not involve "getting the weight into" the swing. A swing is a rotational movement (think hammer throw) where the swinger's weight is not necessarily, or even usually, moving in the direction person is swinging the object. In order to swing an object, force must be directed inward to keep the object from traveling away in a straight line. (see centripetal acceleration here)

So, pushing force is directed in the intended direction of movement. "Get your weight into the shot."

Swinging force is directed inward so an object can be swung in a circular path rather than along a line. So weight, if directed anywhere, is directed inward in a swing.

"Get your weight back" is a better instruction than "Get your weight into the shot" if you're swinging an object.

If you want to push something, then by all means get your weight into it.