It always begins with a serve. Every point, every game, every set, match, and tournament starts with a serve. The first serve is the only no-risk shot in tennis. The second serve is the only second chance in tennis. When your serve goes south it all goes south - you may have experienced this yourself. The converse is also true - when your serve is on, it is all on. We can't all serve like John Isner (fastest serve 149.9 MPH) because we are not all 6'10" tall 245 lbs. However, you can develop a serve that allows you to start every one of your service points on the "higher ground" for your style of game, prevent your opponent from exploiting your serve, and force your opponents to hit balls and take up positions that are uncomfortable for them. Your serve doesn't have to be a 100+ mph screamer to achieve those ends. Sometimes the best serve is a short, 30 mph "pus ball" that temps the receiver into error, but if you make a habit of hitting weak serves, you are going to be watching a lot of returns go by you. To be effective, both your first and second serves must be consistent, deep, well placed and carry sufficient spin and pace to prevent your opponents from taking advantage of it.

The One and Only Service Grip

There is very little variation on the serve grip amongst playing pros. The grip is the continental or "universal grip" but with the addition of the thumb on top of the middle finger (refer to the animation below). The knuckle of the index finger is located over the first bezel after the top one. The little finger hangs over the end of the racket a little. Beyond that, the grip can be spread out or fisty - see what feels best.

The popularity of this grip on the serve is simple; this grip allows one to hit with remarkable pace and remarkable spin at the same time. Spin in the serve comes from two sources; brushing across the ball from low to high and left to right, and pronation of the forearm and shoulder after the ball has left the strings. Wait! What? But! Yes, you heard me right. What happens in the follow through of any stroke is indicative of things happening at the moment of contact. The pronation that occurs in the follow through indicates that a pronation force was present when the racket face met the ball. If there is unopposed pronation force on the racket at the moment of contact, that force will inject both top and sidespin into the ball due to rotational impulse. Heavy spin vastly improves the serve consistency for you and unpredictability for your opponent. It lets you greatly increase the percentages of your first serve and also hit your second serve with as much oomph as your first serve just by upping the amount of spin a bit.

The continental grip "supinates" the racket in your hand which means that with the racket pointing at the target at the moment of contact there is still some pronation left in your forearm. The effort of "going for" that pronation results in pronation force at the moment of contact which adds massive spin to the ball.

The extra spin helps pull the ball down into the court and contributes to confidence on your serves. If the racket face ends up facing the right side fence in the follow-through, you know you met the ball with sufficient pronation force to inject massive spin.

Footwork

Better footwork = a better serve. The importance of service footwork is somewhat paradoxical since the serve is delivered from a stationary position, but improper footwork results in a wildly inconsistent and weak serve:

Serve Footwork
1. Raw serving power is largely dependent upon an upward explosion of the legs.
2. The stored control and spin forces also rely on the power wave generated by the lower carriage.
3. Dynamic balance is essential for a reliable service motion and a reliable toss.
4. Service reliability depends on a consistent toss. An erratic toss = an erratic serve.

One key to a reliable toss is to be transitioning from static to dynamic balance by the time the tossing arm reaches the level of the shoulders. That way the tossing arm does not throw you off balance and force your brain to contort your body and misdirect the ball. There are several ways to achieve this, but the easiest is to start a rocking motion and to start bending your knees before the ball leaves your hand. Your bodyweight moves forward onto a bent front knee - the coiling of the spring that ultimately provides the raw horsepower of the serve.

The Foundations of the Serve

While I grant you that a serve looks nothing like a forehand, both strokes do use the same basic tools to achieve the same basic ends. Both strokes have evolved over 500 years to maximize effectiveness and consistency through the efficient production of control, power, and spin. As a result, the basic requirements of both strokes are identical in function even though they are quite different in form.

The Service Toss

The serve toss is so important it gets its own chapter. Here I will only say that a consistent toss is an absolute prerequisite for a consistent serve. The correlation is so strong that the reverse is also true; if you develop a consistent toss you will inevitably develop a consistent serve.

The Unit Turn

Since you are never rushed on the serve and always start from the same stance, the objectives of the unit turn in the serve are somewhat unique. The serve unit turn is much less violent, much more graceful and much more complicated than in any other stroke.

There are three sets of serving chores that need to be completed during the unit turn. They are:

Unit Turn Chores
1. establish dynamic balance
2. relax the hitting arm
3. toss the ball

Dynamic Balance

The transition from static to dynamic balance starts by rocking the weight from one foot to the other. The sequence takes several forms depending on the initial stance. If one starts with bodyweight on the front foot, the steps are back foot, front foot and bend the knees. If one begins with the weight on the back foot, the sequence is to shift your body weight forward and bend the knees. The knee bend is critical since it is both required for dynamic balance and it prepares the body in two ways. First, bending the knees coils the body in preparation for a vertical explosion of power that starts the power wave. This move is analogous to setting one's weight on the back foot in preparation for a groundstroke or volley. Second, bending the knees allows the server to lean the body back in line with the upper legs, approximately 30 degrees off vertical. I call this the "attack angle", and it defines the optimal orientation of the body throughout the rest of the serve. The angle of attack is often referred to as "arching the back", a particularly dangerous black pearl. The back should never be "arched" in the serve. It will make your serve erratic and your spine a mess.

The next chore is to relax the hitting arm. The move is simplicity itself. From the stance position, one lets the hitting arm go limp and fall to a position behind the back foot where it pauses briefly to allow the toss to complete. This effortless motion enables pace, spin, and control on the ball by relaxing the arm muscles, creating what teaching pros used to call "spaghetti arm." Letting the arm go limp puts it in an optimal state for both the propagation of the power wave from shoulder to racket and to transmute power from the wave into stored control and spin forces during the load.

In the past, spaghetti arm was felt to be something that one could create after the trophy pose as the hitting arm was transitioning into the pendulum. The truth is that muscular relaxation takes time. It must be started early, especially in the serve. The trick then is to keep the hitting arm relaxed throughout the stroke. The arm does not create power in the serve; it only carries it to the racket and stores control and spin forces

Dropping the hitting arm also helps in the toss. When the arm goes limp before the release of the ball by the tossing arm it obviates sympathetic contraction or cross-linking of the biceps of the tossing arm with the hitting arm which can seriously mess up the serve (see Toss the Bouquet Syndrome). The dropping of the hitting arm in the unit turn of the serve is essential for maximal control and power.

All of the forgoing objectives of the turn must be integrated with the service toss:

Serve Unit Turn Basics
• rocking motion
  • convert to dynamic balance
  • set the front foot for vertical power
• rotate hips and shoulders
  • clear the front shoulder for unobstructed toss
  • wind up body for rotational power
• bend knees
  • for dynamic balance
  • windup for vertical power
  • to establish attack angle
• lean back into attack angle
  • creates new rotational axis
  • frees up hitting shoulder at moment of contact
• drop hitting shoulder
  • winds up for shoulder-over-shoulder power move
  • helps launch the toss
• hitting arm goes limp
  • extends elbow
  • "spaghetti arm"
  • muscular relaxation
• tossing arm all the way up
  • completes the drop of the hitting shoulder
  • follow-through for the toss

The Pose

As in all other strokes, the pose is not a destination; its a milestone. You want to pass through the pose right into the lock phase in one smooth motion, but the concept of the pose is particularly important in the serve because it represents a moment in time-space wherein all of the disparate goals of the unit-turn-and-toss phase are fully realized. The serve pose is called the trophy pose because the sculptors who make trophies use it as a model, likely because it looks so so dramatic and so darned painful. In truth it is the moment of greatest tension in the serve; the buildup before the climax, the coil before the strike, the crouch before the pounce. That being said it is nonetheless essential to stay relaxed and to flow through the pose. The serve pose is one of those universals in tennis, and there is perhaps only one major variation; feet apart, called the platform stance, or feet together, called the pinpoint stance. The pros use both, and neither is particularly advantageous, so you can choose the one that feels most natural.

Beyond that the knees are bent about 90 degrees and pointing a titch over the baseline, weight on balls of the feet, body leaned back in line with the thighs, shoulders tilted down and back with the chest facing the back corner of the fence, racket vertical and tossing arm reaching for the sky. That's a lot of detail for something so transient, but within a movement as complex as the serve, it is helpful, almost joyful, to have a moment smack dab in the middle when it all seems to come together for a moment. I suppose one could practice the serve pose but don't. That could lead you to pause there which might result in a hitch in your serve and you don't want that! No, the pose is best appreciated as an attractive but annoying acquaintance - in passing.

The Lock

As in other strokes, the lock phase is brief but vital. It is also the phase most likely to be dropped right out of the stroke, especially if one is tight or distracted. That is a shame since the lock has more to do with hitting a consistent, powerful serve than perhaps any other component of the stroke. Without it you cannot create the stored forces that ultimately create control and spin on the serve. What's left of your serve is a slap instead of a snap.

The service lock and load has been called "the pendulum", and the description is apt. From the trophy pose, one starts by over-reverse-rotating and over-dipping the hitting shoulder just a titch. This move is the backswing proper of the serve, and even players who perform a full lock in the service often forget to perform this tiny backswing. Analogous to the lock in other strokes, this very subtle reverse-rotation throws the racket and hitting arm into a small orbit, in this case, centered around the elbow of the hitting arm. As the small reverse-rotation starts, the wrist-racket combo which is still moving through the trophy pose will first slow then continue falling back behind the tossing shoulder, its weight alone winding up the shoulder and forearm in the supination direction. If one's arm muscles are too tense the pendulum will not happen, if too loose then stretch-shortening will not occur. Setting the tone of the arm muscles in the lock is all up to the hitter and is a common source of service fails. If the racket is stopped or "hitched" in the pose, the reverse-rotation of the shoulders will throw the hitting arm into pronation then rebound back into the pose position. A shoulder hitch is a disaster since the power wave will pull the racket directly up to the ball without a load, so no snaps, no control, minimal spin, and no power; a push serve.

If one's hitting arm remains relaxed (like spaghetti) the lock will succeed, and the power wave will pick up the racket in orbit and catapult it through the load phase and into the lag.

The Load Phase

Power from the serve comes primarily from three sources all triggered at the end of the lock phase:

Serving with Power
• explosion of the legs
  • upward acceleration of the body
• shoulder over shoulder technique
  • hitting shoulder rises as tossing shoulder falls
  • significant power source
• horizontal rotation of the shoulders
  • center of rotation tilted ~ 20-30 degrees along the baseline
  • net rotation of the hitting arm is up and over towards the right net post

All of these forces converge at the hitting arm shoulder at the end of the lock phase and accelerate the shoulder up and over the body. The inertia of the racket head resists this force accelerating the pendulum motion behind the server's right shoulder until the arm reaches a critical point of maximal shoulder and forearm supination, shoulder extension and elbow flexion.

In essence at that moment the orbit around the elbow has tightened and vanished as the pronator muscles of the shoulder and arm are stretch-shortened to their limits. At that point, the racket begins to be dragged behind the wrist in what seems to be almost a straight line up to the ball but is itself a broader orbit around the body's net axis of rotation. So begins the lag phase. The extreme contortion of the hitting arm during the load phase and the resultant severe stretch shortening likely accounts for the fantastic precision demonstrated by competent servers: The greater the stored control force, the more directional momentum delivered upon impact.

The Lag Phase

The lag phase is the period when the remaining energy of the power wave is consolidated into racket head speed and ultimately the pace of the ball. The key to achieving optimum racket head speed is the proper application of leverage. The essence of leverage in this context is the ability to change the length of the lever arm through which the power wave is acting on the racket head. As the head increases in velocity, the arm changes from a short lever applying high torque at low speed to a long lever applying lower torque at higher speed. The change in the length of the lever arm is accomplished by unfolding and extending the wrist, elbow, and shoulder throughout the lag phase. The racket addresses the ball on edge, like a tomahawk, knifing through the air until, mere milliseconds before contact, the pronation forces are released in the explode phase.

The Explode Phase

As the power wave dissipates, as one relents from driving the racket up towards the ball, the forearm., wrist and racket catch up with the rest of the arm and make violent contact with the ball. As the acceleration ebbs, the stored forces in the arm and forearm are released and deliver control and spin forces to the ball. Unlike most other strokes the stored pronation forces in the serve are so formidable that they reveal themselves before the moment of contact. The racket face flips over; from facing the left side fence (for a right-hander) before contact to facing the right side fence immediately after contact. You synchronize the entire service motion to this 'reveal' of the racket face: the instant that the racket face opening up to meet the ball facing more or less parallel to the net.

Captured within this moment are all of the myriad mysteries of the serve. How can one address the ball when the racket face is only pointing at it for a few milliseconds? How does one control the ball if not by directing the racket face towards the target? How is topspin, generally thought to come from brushing up across the back of a ball, applied to a ball that is at the very limit of our reach over our heads?

The very fact that the racket face flashes across the ball, only momentarily pointing at the opponent's service box, is, to me, one of the most potent confirmations of the importance of impulse for control. There is NO WAY that Federer, Nadal or anyone else could guide a ball to the opponent's court "T" by timing the moment of contact such that the five milliseconds the racket is in contact with the ball encompasses the three milliseconds that the racket face is pointing at the target. The direction of the racket face at the instant of contact cannot meaningfully affect control. The direction the racket head is traveling at the moment of contact is towards the right net post, so that does not seem to be the source of control. That leaves stored forces and impulse.

As for topspin, I am going to go way out on a limb to try and explain that one. I have heard and read many explanations for how one puts topspin on a serve and no one explanation has satisfied me completely. I believe what is happening is this: The racket is traveling up and towards the net post when it encounters the ball. If you don't fully pronate at that moment and instead carve around the outside of the ball, you get mostly sidespin with a little topspin. That makes sense since the racket is likely pointing somewhere in the vicinity of the target service box which is not the same direction it is traveling so there should be spin and it should be a combination of sidespin and topspin. Now if you carry significant pronation force to the ball, such that the follow through demonstrates extreme pronation, there will also be spin added to the ball, and depending on the contact point on the surface of the ball that spin is likely some topspin and some sidespin in a direction opposite that which is added by brushing. The side-spins would then cancel each other, and the result would be nearly pure topspin. That is what you call a theory, and I whenever I expound one I remind myself of my favorite saying: "Another pretty theory, brutally murdered by a vicious gang of facts!"

The Follow-Through

As with all other strokes, the follow-through of the serve is nothing more or less than a full report on what happened earlier in the stroke. Consequently the follow-through is not to be controlled, it is to be observed. The earliest part of the follow-through is the most revealing, and contains information about your body orientation at the moment of contact, stored control and spin forces, the timing of the explode phase and general muscular tension.

Ideally the hitting arm in the follow through should slightly flexed at the elbow, pointed toward the net post, with full pronation in the shoulder and forearm and a moderately (10% beyond neutral) cocked wrist. Identifying the absence or distortions of any of these findings can lead one to an underlying problem:

Troubleshooting the Follow-Through
1. absent pronation
   failure to load
   • shallow or no pendulum
   • hitch at the pose
   • tightness in the lock
   failure to explode
   • Hot Shoulder Syndrome
   • late or early explosion
   hips or shoulder over-rotation
   • failure to slow the shoulders
   • orienting body to net instead of net post
2. abusing your knees (with the racket)
   hips or shoulder over-rotation
   • shoulders parallel to net at moment of contact
   • pose not sufficiently closed
   • turning towards net instead of away on backswing proper (lock)
3. ulnar-flexed (un-cocked) wrist
   insufficient leverage
   • failure to relax during unit turn
   • tension in the lock
   • shallow pendulum
   • compensation for too-vertical attack angle
   • pushing (half-serve or beginner serve)