As many of you who follow this column regularly know, I photograph ATP and WTA events, particularly the Pilot Pen. Last summer, I took some video in addition to my still images of various players hitting virtually all the strokes in the game.

Concurrent with this photography, I happened to start reading one of the books in my tennis collection, which dates back to the early 1960’s. Needless to say, the modern game has changed in many ways.

However, as a result of these two activities, I came to an insight regarding the modern game that previously had not come to my conscious attention. This is how differently the wrist is used in the modern game.

Historically, textbooks on tennis will encourage players to keep a firm wrist on all strokes. Of course, this advice predated the emergence of graphite racquets and the string technology associated with the modern game.

In reviewing the slow motion footage from last year’s Pilot Pen, I realized that the firm wrist theory has changed significantly. During the telecasts of this past U.S. Open, I videotaped virtually every match that reached broadcast and examined these from the perspective of how modern players use their wrist when producing strokes.

My initial insights from the Pilot Pen were confirmed when I had time to truly examine the footage that I recorded from the U.S. Open.

With this in mind, I am dedicating this month’s column to my hypotheses associated with the use of one’s wrists in stroke production. I state that these are hypotheses because I have not found much corroborating information on subject. In truth, I have found little that speaks directly to the role of wrists in the modern game.

So, here I go.

Belying what I have just stated, there are studies that indicate the importance of the wrist in serving.

Every serve requires pronation. This, however, is more of an arm/wrist movement. Pronating as one serves is what prevents us from hitting the ball with the edge of our racquet frame.

For right-handed players, the pronation is what one would encounter if he/she unscrewed a light bulb. For lefties, the pronation in serving would be the same motion associated with screwing in a light bulb.

In a very real sense, there is some wrist movement involved in pronating. But, this is not what we normally would perceive as being a wrist movement.

Pronating during the serve is one way in which a player can generate more power in her/his serve. If one makes a more deliberate, and perhaps, pronounced pronation, the serve usually has more pop to it.

Recent studies using very high-speed video analysis (this results in ultra slow motion footage) indicate that bending the wrist at the moment of impact can greatly increase the power in a serve. Generally, the wrist should be a bent back a bit before the contact point and move in a forward snap when making contact.

I have experimented with exaggerating my wrist bending while practicing first serves. Not having a radar gun to measure the increase in speed, I cannot tell you specifically how much more power there is when the wrist is fully and forcefully snapped. But, I assure the reader that it is noticeable and pronounced.

Spin serves (slice, topspin and kick) also benefit from more deliberate wrist action at the moment of impact.

A slice serve, as I am sure most of you know, is one that has sidespin. This sidespin makes the ball curve to the right or left when bounces. Of course moving the arm away from the body and stroking the ball in a manner that crosses the back of the ball produces the essential spin. But if one adds some deliberate wrist action to this racquet motion (again, at the moment of impact), the slice effect can be greatly enhanced.

Topspin serves necessitate that forward spin be imparted to the ball. This is in major measure produced by attempting to toss the ball a bit behind one’s head. If a player tosses in this manner and hits upward on the ball, the topspin is produced. This can take some practice to master, but once a player has discovered the proper combination, it is a fairly easy to consistently produce this serve effectively. Here again, if wrist movement (upward and forward snapping) is added to the racquet motion, the overall spin can be enhanced significantly.

Kick serves combine both slice and topspin ball movement. By adding an upward and side snap of the wrist, the kick effect (a high bounce and curving to one side) will generally be very pronounced.

If there is one stroke in this game that can greatly benefit from increased wrist motion, it is the serve. Allied with this, overhead smashes can be enhanced when one snaps the wrist forward and downward, at the moment of impact.

The mechanics of serving is being better understood each day, thanks to the application of high-speed video analysis and controlled testing. But, the general consensus is that wrist snapping being included in the service motion can be very desirable.

In the "days of old," tennis players were encouraged to keep a firm wrist when hitting the forehand groundstroke. Of course, this was in the days of wooden racquets, eastern forehand grips, long strokes and surfaces that often times did not produce a high bouncing ball (e.g. grass).

Well, the modern game is based upon powerful, topspin forehand "groundies." Graphite racquets, polyester strings and semi-western/western grips have made this type of forehand groundstroke the norm…not the exception.

Still, the wrist, when using a semi-western or western grip, can help produce more topspin. With more topspin, one can hit a ball harder and still find that it lands within the white lines.

More and more of the pros on both tours are exaggerating the wrist motion at the moment of contact when hitting forehands. The wrist is frequently bent during the backswing so that the racquet head is pointing a bit towards the ground. At the moment of contact, the wrist is brought "upward." Really, the wrist movement is forcing a greater brushing up on the back of the ball. This wrist movement can greatly enhance the amount of topspin that is produced. The forward motion of the racquet can be made more powerful. The combination can be devastating to opponents.

If one watches the finishes of players who are using this wrist action in their forehand groundstrokes, the finish is not "over the shoulder." Rather, it is more across the body…with the stroke taking on a somewhat "windshield wiper" look.

The first player whom I noticed used this combination was Andre Agassi. It is no wonder that he could virtually hit the cover off the ball and still find his shots landing in bounds.

One of the advantages of a two handed backhand is that the player can actually incorporate wrist motion into the stroke. Like the forehand, the racquet can be taken back with the racquet head somewhat pointing at the ground. Then at the moment of impact, both wrists can be snapped in a manner that brushes the strings upward against the back of the ball. The result? More topspin. Add a more deliberately powerful forward motion to the racquet, and you have another devastating groundstroke.

Rafael Nadal is somewhat unique in that he will actually use wrist action to produce an angle to his two handed shots. When he is forced wide to his backhand and on the run, he will make contact with the ball and use a wrist snap to produce a trajectory that will force the ball to the crosscourt angle. It is truly amazing to watch how effectively he uses his wrists to produce an angle where one would seemingly not be possible.

I suspect that as juniors adopt his technique, we will see more of this in the pro ranks in the future.

These three strokes are generally not ones that can utilize a wrist snap. More often than not, these strokes require what the TV commentators would refer to as a "firm wrist."

The term "firm wrist" usually has no meaning to the average individual. To prove my point, try to make your wrist firm at this moment. Right! How does one do this? There are no muscles in our wrist, and unless you have a brace on the wrist, it naturally wants to bend.

A firm wrist can be understood, however. What is really implied by this term is that the player grips his/her racquet more firmly at the moment of impact.

In tennis, we want to have our arms be as relaxed as is possible throughout strokes. With volleys, we do not really want to stroke the ball. Rather, we want to block the path of the on-coming ball, and maybe produce a bit of under spin as we make contact with the ball. Half volleys are really based on good timing, and may or may not allow for some wrist action. These are the most difficult strokes to practice in that there are so many different varieties of half volleys that one may be forced to hit. Essentially, half volleys are a reaction shot. You do what you can given the situation.

One-handed backhands, especially driving shots, generally do not benefit from any wrist action at the moment of impact. Tomas Muster would put a bit of wrist motion into his topspin backhands on clay…but this is the exception, not the rule.

So with these three categories of shots, it is safe to say that wrist motion should be avoided. (For those of you who feel compelled to write and express your disagreement, please realize that this is a generalization and holds true for most, but not all players).

In teaching volleys to students, I have found that once I put the mystery of the "firm wrist" to rest, the students’ volleys greatly improve. Simply tightening your grip at the moment of impact will provide the necessary stiffness to block the on-coming ball with authority.

So, I would encourage each of you to experiment with wrist movement in your strokes. There is, however, one caveat that I would put forth. If you have had any wrist injuries, or if in experimenting with these changes you experience discomfort in your wrist, stop the experiment. This advice may be more applicable to senior players. Please take heed.

If you are able to increase power and spin in your strokes as a result of increased wrist action, I am certain that you will be well on your way to becoming a tennis overdog!