The Serve: Where Are We Now?
Part 1

John Yandell

So as we start our 18th year it's an excellent time to summarize some more of the things we have learned from the study of the strokes of the best players in the world in super slow motion—and how that applies to you.

A couple of years ago I did this in a series called The Forehand: Where Are We Now? (Click Here.) Now in these articles let's do the same for the serve.

Variety

If we look at the variety of motions among the top players, they can appear bewildering. There are major differences in starting stances, movement of the feet, windups, backswings, toss heights, tossing motions, amount of leg drive, amount of body turn, landing positions, followthroughs.

Time after time over the years I have worked with players who noticed certain parts of the motion of top players and tried to copy those parts. Often what stuck out to them however was secondary or idiosyncratic and not core.

So are there core fundamentals across all the variations? I say yes. And these are critical for all players to develop.

The Racket Path

When you look at all the factors that contribute to racket speed, spin, accuracy, and consistency, the basis is always the racket path. When I work with players, especially below the pro level, this is where I start.

There are 3 key positions in the racket path. The racket drop, the contact point, and the extension of the forward swing.

Regardless of the backswing shape and timing, good serves all reach the racket drop with the racket falling along the right side of the body, more or less perpendicular to the torso. A great majority of the club and recreational players I have filmed don't make this position and start the upward swing with the racket angled across the back and the tip of the racket shy of the full depth of the drop.

Other Factors

A lot is made of the so-called power or trophy position and whether the movement through this is continuous, faster or slower, or has a slight pause. But all this is irrelevant if the racket and arm don't continue to the drop position.

A lot is also made of the external or backward rotation of the upper arm in the drop. For some great servers this means the drop swings slightly further out to the player's right, so that the forearm and racket are at a slight angle to the torso beyond perpendicular.

This is technically called external shoulder rotation. It means the upper arm rotates further backwards in the shoulder joint, and theoretically, further is better.

This more extreme drop position can increase the rotation of the hand, arm and racket in the upward swing, probably adding an increment of racket speed. Great if you can do it naturally but it takes amazing shoulder flexibility.

But the perpendicular drop is fundamental. Players shouldn't try to force it further unless it is natural.

Upper Arm

A more important factor to look for at the drop is the position of the upper arm in relation to the line of the shoulders. For great servers, the upper arm is basically in line with the upper chest, that is, extending straight out from the shoulder joint.

Again this is related to natural ability to rotate the upper arm backwards in the shoulder joint. Very few recreation players have this kind of flexibility.

So to make the racket drop position, most players need to raise the elbow and/or tilt it forward out of the line of the shoulders. But the ability to do this is usually related to the shape of the backswing.

Backswing

A big variable among pro servers is in the shape of backswing or windup before going into the drop. As is well known, players like Andy Roddick have an extreme abbreviated motion in which the racket goes up and to the outside before moving downward into the drop.

Roddick himself has an awesome racket drop that includes the outward swing to the right with the angle of the racket going beyond the perpendicular drop position. But, with only one or two exceptions I have seen in 20 years, recreational players and even high level junior players who try copy this motion end up actually restricting the depth of the drop and end up with the racket at least partially on a diagonal across the back.

I also saw this when I was working with Paul Goldstein, the Stanford men's coach, when he was playing on the tour and about 50 in the world. Paul had adopted the abbreviated model in search of additional racket speed and mphs.

But the change had the opposite effect, restricting his drop. The solution for Paul was to open up his windup, using a circular backswing shape. You can read about that process by Clicking Here.

The Wind Mill

One of the drills I asked Paul to do was what I call the windmill, basically swinging the arm and racket down, back, and up, then forward and around in a circle. Then in the actual motion you take the windmill motion to the top and just let the arm relax and racket drop.

As the article with Paul shows, the effect of opening up his windup was an immediate increase in the drop to the checkpoints with the racket along his side. The impact was immediate in increased ball speed, and Paul and his coach both loved it.

The next week Paul was playing in a tournament where we were also filming. Compared to his previous radar gun readings, he picked up 10mph.

Other Options

There are top servers who have used this same more circular windup pattern. John McEnroe was one. Mark Philippoussis was another. Both had great racket drops.

Other top servers like Pete Sampras and Roger Federer are somewhere in between circular and abbreviated. This means they start the elbow bend earlier when the racket is moving upward in the backswing instead of waiting for it to get closer to the top.

But the point isn't the shape of the backswing. The point is does the windup deliver the racket to the full drop position.

Why Drop?

So why is the full drop so important? Because the movement from the drop to the contact point is the interval that generates the overwhelming majority of the racket speed.

In a quantitative study of Pete Sampras's serve I did in conjunction with Brian Gordon (Click Here), we found that in 1/10th of a second in the movement from the drop to the contact, Pete generated two thirds of his overall racket speed, going from 30mph to 90mph.

But that drop position is important for another reason. It is critical to the correct racket path up to contact. Players with diagonal drops across their backs not only lose racket head speed, they approach the ball at the wrong angle, coming from left to right rather than more directly upward to contact.

This movement of the racket up to contact has been called the most complex motion in sports. (Click Here.) That may be true but that doesn't make it difficult or impossible.

It is driven by the elbow extension and the internal rotation of the upper arm in the shoulder. There is also movement in the wrist.

The wrist is in a laid back position at the drop. In that 1/10 of a second in the movement to contact, it goes from laid back to neutral. More on the wrist movement below.

Racket Head Angle

Another key point about contact is the angle of the racket head. It should tilt around 25 or 30 degrees to the left on a first serve, and more, up to 45 degrees on a second.

Why? This is what creates the top spin component, critical on both deliveries. That can't happen if the tip of the racket points directly upward to the sky.

This means the ball placement on the toss is also critical. It needs to be somewhere between the shoulder and the side of the head on a first serve, and more to left on a second, say roughly over the top of the head on the second and more to the left depending on the spin level the player is comfortable generating.

Equally important is the position of the toss, front to back. On a first serve, the contact point from the side view should be roughly even with the front edge of the face. On a second it is further behind, roughly over the top of the head.

Many players struggle with toss placement, and there are a range of possible tossing arm motions to achieve good ball placement. I will have more to say on this in a future article and well as articles on the toss from a couple of great teaching pros who are Tennisplayer contributors.

Wrist Snap?

But back to that wrist movement. Some researchers say the movement of the wrist up to contact happens naturally—the racket weight is in effect moving the wrist. Others have found actual muscle contraction.

The key point though is the neutral position at contact. So is it a "snap?" I say no because there is not continued forward flexion after contact in the serves of great players, or in good serves by players at all other levels.

But "snap the wrist" on the serve continues to be a staple in teaching lexicon. Unfortunately one that is destructive, limits potential, and is a risk factor for injury.

You can see the negative effects of the forward snap after contact even at the highest levels. For example Kei Nishikori. (Click Here.) Or Andy Murray, Just to name two. (Click Here.)

And why is this snap a negative? Because it cuts of the main driver of the upward swing—the internal rotation of the hand, arm, and racket from the shoulder.

After contact good servers all continue to rotate the arm as a unit until the racket face has turned over about 90 degrees, ending with the top of the racket now pointing down perpendicular to the court. This continued rotation is what maximizes racket speed.

This movement after contact is sometimes incorrectly called "pronation." Pronation is actually the independent rotation of the forearm in the elbow socket. It's been shown that it is not a part of the hand, arm, and racket rotation up to and after contact.

Pronation is ok as a teaching term though, so long as it referrers to unitary hand, arm, and racket rotation and the edge of the racket face turning over after contact.

Extension

I call this point where the racket edge has rotated after contact the extension point. Typically at the point the arm will be extended more or less straight out and roughly parallel to the court.

It's the third key position in the swing after the drop and the contact. When you make it, it ensures that you have maximized the effect of the shoulder driving the swing. It's analogous to the extension point on the ground strokes.

Good extension is key to maximizing the racket head speed at contact. After that the arm just falls forward and across to the player's left side. Sometimes you then also see the wrist relax and flex slightly forward which is sometimes seen as "snap." But in fact is just an after effect in the deceleration phase.

Image and Feeling

So if you buy the importance of these 3 key positions: racket drop, contact, and extension, how to do you actually make them happen? The answer is physical and mental modeling.

Do a shadow swing and move to the drop. Get the checkpoints correct. Now close your eyes and imagine how the position looks and feels inside your mind and body.

Now, whatever windup you are using, move from the start of the serve to the drop again with your eyes closed. Use the image of the checkpoints as a mental blueprint.

Repeat this until you can hit the checkpoints accurately and naturally with a relaxed motion.

Now move to the contact point. Again close your eyes and imagine the image and the feeling. Now go to the extension point and do the same.

Now go back to the drop and connect the dots. Move with your eyes closed to the contact and the extension.

You are ready to hit. Video yourself and see how close you are to the positions. Likely at first you will be somewhat off on 1 or 2 or 3, or even all 3. Using the video to gauge your progress. Think of the change as a series of successive approximations.

As you master the positions, you'll see increases in ball speed and in the topspin component, but the whole motion should feel easier and more relaxed. If you have a radar gun, measure the speed before, during and after the work!

So that's it for Part 1. Next we will start to examine the many variations in the other components of the serve and recommend the ones most likely to work for you.