Control

How come talented players never seem to miss the sitters? Sitters are the great levelers of tennis. Anyone can, in theory, put away a shoulder-high volley with a minimum of muss, fuss or technique. You generally have a whole court to hit into and lots of choices on how to win the point. About the only incorrect choices are to drive the ball straight down into the base of the net or to float it over the baseline; over that immense expanse of open court that yawns before you. So why do talent-plus players usually choose correctly and you usually flub it? These are the unconscionable errors that starve your victories, infuriate and embarrass you to death. The talentoids also seem to hit everything else more consistently than you despite your superior stroke mechanics and unmatched desire to win. How do they pass you over and over by just sticking out their rackets? How do they reach behind themselves on overheads and hit well-placed winners? Why don't they bunt their groundstrokes over the baseline as you do on every other attempt? It isn't because they are hitting the ball softer; you have tried moon-balling or pushing the ball many times, and it reduced your percentages. So what is the deal?

The "deal" is control. A-players know how to inject directional control into every ball, and it is always a priority second only to putting the racket face on the ball. This mysterious power to control their shots is why their reach shots, trick shots, and half volleys, despite the lack of mechanical advantage, are often their best-placed shots. It seems that the more anxious they are about getting to the ball the more conscientious they are about injecting control. In that way, control is simultaneously an offensive and defensive weapon: Its a twofer! Beyond that, the mechanics of control are (almost) completely occult, so control is the ultimate stealth weapon! Anyone who has faced a player who seems to be able to completely and unexpectedly change the direction of the ball to their advantage knows how magical control can seem.

The Foundations of Control

If this is the first article you have read in this site, you might be surprised to hear that the physics around control is based on the idea of impulse. Otherwise, I bet you saw that one coming a mile away. Anytime you want to influence the direction of the ball you must use impulse. Impulse itself is invisible and occult. The general feeling behind impulse is called "snap" and the only visual manifestations of snap is the sound of the ball coming off of the strings and a secure, solid feeling in the hitting arm. If there is a lovely, lively, musical ping or pop as the strings meet the ball, you have created impulse and taken control over the direction of the ball. "But how do I determine the direction the ball will go?" you demand, intelligently, to which I quip "Usually anywhere but the base of the net or the back fence is good!" By which I mean anywhere but where the ball itself wants to go by virtue of its incoming direction, speed and spin because when an undisciplined ball hits a moving racket, bad stuff happens. Just getting the ball turned in the general direction of clearing the net and avoiding the sidelines is a start. Staying inside the baseline is a bit trickier, but if we can take care of the most egregious errors, then that last can be greatly improved with the addition of spin to the ball. Indeed, the addition of spin turns out to be one of the foundations of control but not for the reason you might think. The way that spin changes the flight path of a ball is important, but not the primary reason for adding spin. The act of adding spin to a ball makes directional control possible through the geometry of spindirection.

Spindirection

I made this word up because it perfectly describes a concept that is central to achieving hegemony over a tennis ball. The traditional way of adding spin to a ball is to strike it with a racket that is moving in one direction but whose face is pointing in a different direction. If the racket is pointing forward but moving upwards, one imparts topspin. If moving downwards, it imparts underspin. Obviously the face direction and path of the racket can't be at right angles to one another, or the only interaction they can have is to bump the ball with the edge of the racket, so the angle between them is somewhere between 0 degrees (flat - no spin) and 90 degrees (edge bump) usually between 30 and 60 degrees - the angle-of-attack of the racket head. The bigger the angle, the less pace and the more spin that are imparted to the ball. This balance between pace and spin was very annoying to A-players who wanted to hit the ball very hard with lots of topspin, so they instinctively experimented with other ways of adding topspin to the ball. Somewhere along the line, they discovered that they could add spin and control that was independent of either the path of the racket head or the direction the face was pointing as long as they added a subtle snapping motion to the stroke. Thus they could hit the ball with a somewhat closed racket face (i.e., pointing more towards the ground) and only a slightly low-to-high racket head trajectory but still direct the ball up over the net with lots of topspin on it. Decreasing the angle of attack of the racket allowed a flatter looking stroke and achieved more spin with more power with a racket trajectory and orientation of the racket face that optimized solid ball contact! Voila!

Hello — Creating Spin with Indirection: When your racket head is moving, and the face of the racket face is pointing in a different direction, you produce spin. If you are trying to control the ball by pointing the racket face at the target or moving the racket head along the proposed flight line, as has been taught for the last 500 years, then how do you add spin? More importantly, how do you direct the sweet spot from where it is in the backswing to where the ball is going to be at the moment of contact? You can't. Give it up! That is not how the ball is bent to your will.

This technique worked for slice as well as topspin. Cool! No-one seemed to question the reason for this miracle - it just worked. "Snap the wrist" and Hazzah! Spin, power, and control all at once! A-tennis was invented! The real miracle was the control. There was more control available from this technique than from simply pointing and moving the racket face along the desired flight path - a technique taught to beginners for eons under the rubric "follow through the ball towards the target". (A-players never do that themselves, but teaching pros still seem to believe that this is a foundational technique that is good enough for B-players. In truth, I have found that anyone with real talent will eventually, naturally evolve away from it even if they don't figure out that it is complete horse manure.)

Hitting With Snap: The "panic volley" performed incorrectly (left) and correctly (right). The subtle whole-arm 'snap' is what A-players use to take control of the ball. Executed with a loose grip, relaxed arm and precise timing it gives them the power to redirect the ball. B-players rush to get the racket in front of the ball, get it there too early and don't store control forces on the way. The ball comes off their racket with a random vector that yields to the ball's incoming direction, speed and spin, not the player's will.

Hitting with Snap

The habit you must cultivate is to hit every ball with a subtle snap of the wrist. To snap the wrist, you must bring the racket back then forward along an imaginary curve that describes the motion of the wrist and racket head. It should not be straight back and then straight forward through the ball lest you violate the absolute law of spindirection. For a slice, it will be up-and-back then down and forward. For topspin, it is down and back, then up and forward. The key to back and forth is to store force in the muscles of the forearm that will be released into the ball on contact, delivering linear impulse for control and rotational impulse for additional spin.

This works for a snap volley (see above) as well as the serve. The only difference between shorter strokes and longer strokes is the addition of a lag phase between the storage of the force and its release int the ball. The lag phase has only two functions; to build up racket head speed for pace, and to contain the stored forces until the instant before the moment of contact with the ball. The essence of control over the ball in tennis is snap. Without snap, the best you can ever do is stick out your racket and pray.