Of all the challenges that trouble the talentless, managing modulation is the most pernicious. How often have you asked yourself "How hard should I hit this ball?" This soul searching is a ubiquitous question in stroke production because muscular effort is one of the few parameters of a stroke that you can affirmatively control. You cannot "adjust" your timing, balance, accuracy, speed, quickness, and rhythm on the fly, but you can vary the 'oomph' you pour into each stroke. So how do you decide how much raw power is too much or too little? What is at stake? The power that one injects into a stroke is ultimately responsible for all of the pace, control and spin produced, so there is certainly an argument for the proposition that some power is always necessary. The ill effects of too much power seem obvious, but if too little power is bad, how can too much power also be bad? The answer is found in the principle of modulation.

To understand the risk of generating too much power you must stop conflating the production of power and its result - pace is not power. Ultimately what motivates a stroke is muscular effort - the contraction of muscles in the legs, trunk, shoulders, and forearm that accelerate the racket head towards its fateful meeting with a ball. It is thus natural for simple-minded dolts such as myself to equate the magnitude of the input - the 'oomph'- with the quality of the output - the depth, spin and especially pace that are produced. It all gets tangled up in the concept of 'power,' i.e., more oomph means more power. To make matters much worse, once I learned about impulse and came to understand the intimate connection between power and control, the temptation to expend as much muscular effort as possible on every stroke became irresistible. Indeed, as one pours more and more energy into a stroke one can see, feel and even hear the stigmata of increasing control; the tightening of splash points around a target, the ball nose-diving towards the safety of earth, the fine vibrations of the racket as the ball embeds itself in the strings and that glorious 'ping' sound that proclaims your mastery over the ball's flight path. "Power GOOOOD!", I thought: More power - more good!

At some point, as one leans more and more into the ball, one starts mishitting the ball into the ceiling, burying it in the net or testing the structural integrity of the backstop. One's balance goes all flooey, and the pace of the ball begins to actually diminish with increasing effort. I call this phenomenon "overmodulation".

Modulation in the context of the power wave theory of tennis describes how the mechanical power wave uses your body as a medium through which it reaches the ball. It is important to remember that the body is a rather poor medium for the propagation of power. Even when one is stroking with fluidity and grace, there is considerable loss energy and fidelity of the wave before it can animate the wrist to affect the ball. Stiff joints, tight muscles, and poor stroke mechanics blunt and distort the wave and can decrease or increase the velocity of the wave thereby throwing the delicate timing of a complex stroke into chaos. If you produce too much power, you can easily overwhelm the ability of your body to carry the power wave from where it is produced - the source - to where it is used - the sink. If your shoulders accelerate too quickly, for example, your arm muscles may not be strong enough to bring the racket face around to the ball. If your legs explode too forcibly in the serve, the muscles of your back and torso will not be able to carry that power to your shoulders resulting in an inaccurate and weaker serve. I term the creation of a power wave that is too strong "overmodulation". I believe that the reality of overmodulation is the truth that lurks at the heart of one of the blackest of black pearls; the myth that states that hitting softer gives one more control than does hitting hard. This "softer the better" theory has rattled around in the back of my head since I was 16 years old and poisoned my game. If it were true that all you have to do to get control is to baby the ball, we would all be pushers. In fact, without generating some power to create impulse one cannot seize control of a ball, a point or a match.

Overmodulation

Thus while it is false that pace is the enemy of control, what is true is that there is a practical limit to the amount of power you can pour into any stroke. You can generate as much pace on a ball as you wish and still maintain control if you derive that power from proper mechanics and leverage. Using brute force to create power, also known as "muscling" the ball, is always counterproductive to the creation of control, spin, and even pace. I dislike the word "overhitting" to describe muscling the ball as it seems to rule out hitting with pace and depth. I prefer the term overmodulation, since it allows one to thump the ball, if appropriate, but still cautions against muscling the ball. Overmodulation means pouring so much power into a shot that whichever part of the body is weakest, tightest or stiffest cannot handle it. Everything after that part sees a blunted and distorted power wave, and the result is a disrupted, mistimed stroke lacking the control and power you are working so hard to produce. A classic example is the shoulder high volley that you have a little too much time to hit, so you lean into it with all the power your legs can muster, but your wrist can't handle that much power and allows the racket head to lag. The ball ends up hitting the back fence. More subtle examples of overmodulation include dragging the racket up to increase topspin, over-pronating on the serve and stuffing forehand drives into the center of the net in an attempt 'cover' the ball by forcibly pronating the forearm. Interestingly, that last example of overmodulation commonly plagues Federer's forehand, proving the ubiquity of this complaint.

Avoiding Overmodulation
• loose grip!!
• listen and feel for 'snap'
• maintain balance
• don't 'muscle' the ball
• avoid grunting

Avoiding overmodulation is not complicated; be aware of the phenomenon and try to keep the peak power level comfortably within the capabilities of your body. Here it is the sense of your self - the totality of your mind and body - that is the most helpful. I say that with no small degree of frustration since I find corporal self-awareness challenging to say the least. One should not ever try to avoid hitting with pace, push the ball nor truncate a stroke. Strokes must be complete and should be fed enough power to maximize pace, spin and control.

Undermodulation

The sin of overmodulation is not motivated by an excess of vanity or aggression nor a lack of good judgment or caring; it is a failure of moderation. With that in mind, we should remember that epic failure arises whenever we pour too much or too little muscular effort into the stroke. Optimal modulation is to physics what the Zone is to psychology. The Zone is a psychological state of optimized mental energy, and it has two exits - over and under stimulation. Both are bad. Similarly, under-hitting is just as bad for your strokes as boredom is for your game. Underhitting leads to a failure to produce enough control and spin to keep the ball in play. It results in short sitters and missed opportunities. Most poignantly, under-modulation will treat you to the profound frustration you experience when you persist in making errors even though you have surrendered any pretense of power and descended into a state of pathetic pushery - a practice that will rip your psyche out of the Zone and cast it down into the deepest levels of Tennis Hell.