Revisiting the Wisdom of Mr. Jack Kramer

We wanted to close out the year 2011 by bringing your attention to the tennis performance wisdom of arguably, one of the greatest minds of tennis history, the late Mr. Jack Kramer (1921-2009).

For those of you who aren’t especially familiar with the history of tennis, Mr. Kramer was not only one of tennis’ great Immortals as a player (twice Singles Champion at both Wimbledon and the US Championships held at Forest Hills - the forerunner of today’s US Open), but played a seminal role in developing professional tennis into the global sports institution it is today.

In 1977, Mr. Kramer published an instructional book (co-written by Larry Sheehan) titled “How to Play Your Best Tennis All the Time”. In this book, Mr. Kramer spelled out in very simple, clear and concrete terms the fundamental truths of how to become a successful tennis player – regardless of your “talent level”.

While it may be true that certain stroke mechanical ideas that Mr. Kramer presented back in 1977 have evolved considerably since then, the general strategic and tactical concepts he presented in his book have and will stand the test of time.

Here are Mr. Kramer’s own words on how to perform like a top player (pages 15-18):

"Why do you suppose Ken Rosewall could reach the final at both Wimbledon and Forest Hills in his fortieth year? Why are Pancho Gonzalez, Rod Laver, and Roy Emerson so tough to beat even they’re also well past their playing prime? Why is Pancho Segura in his middle fifties such a threat on the burgeoning pro senior circuit against players ten years his junior?

The answer is that, though the stamina and power of youth may be gone from their careers, these players possess a defensive game that is as sound as it was back when they were winning most of the matches they played.

The defensive game is based primarily on control of the ball on serves and on groundstrokes. It requires knowledge of how to produce spin on shots through the action of your racket in the stroke, and a sensible “percentage” application of the shots available to you. It is the key to developing the steadiness and consistency on the court that causes an opponent to make errors and give you points. It is indisputably the only logical style of play for the majority of weekend players, and it has the added advantage of being a style that does not really wear with age, or rust too much from neglect. It is effective at every level of play, from novice to pro.

Coming from Jack Kramer, this emphasis on defensive baseline play, with a high priority given to forehands and backhands, may sound surprising. You may have heard of my reputation as “the man who institutionalized the Big Game in tennis,” or as “the serve-and-volley player par excellence.”

Actually, I learned a steady defensive style of play first, and I’ve never regretted it.

I was eleven when I took up tennis. In those days—in the 1930s—the big names in the game were Bill Tilden, the Englishman Fred Perry, Don Budge, and Bobby Riggs. Budge and Riggs, only a few years my senior, were the young lions of the tennis world as I started competing.

With the possible exception of Vines, who generated such phenomenal power on his serve that it ws only natural for him to lean on that stroke through many a match, all the leading players of the age overcame their opponents by controlling the ball with shots played from the backcourt. They concentrated on returning serve adeptly, so the opponent could not safely come in following serve. They seldom attacked immediately behind their own serve. The hit solid, well-placed forehands and backhands until they forced a short, weak ball, and then they did attack, moving to the net to complete the kill with winning volleys.

These were the players on whom I modeled my own game. As a result, I grooved a solid forehand and a dependable if not spectacular underspin backhand, long before I paid much attention to volleying at all.

There was another good reason to specialize in groundstrokes before all else in those days. Most major junior competition of the day was held on slow surfaces where duels from the backcourt were inevitable.

Only later, when I began to compete on the fast grass surfaces on which the big men’s titles were contested in those days—Wimbledon, Forest Hills, Longwood and the various Davis Cup sites—did the extra-strong serve that had evolved in my game begin to give me a decided advantage. To exploit the weak returns that were made off my fast, skidding wide serves on grass, I hustled in to intercept the opponent’s return in the air and volley it away. I wasn’t afraid to be lobbed, if my first volley had not scored an outright winner, because along with my serve, I also possessed a naturally strong and dependable overhead smash. I could cover all but the most skillfully played lobs and put them away for the point.

This combination of serve, volley, overhead was the winning combination in my game that gained the most publicity.

Without the groundstroke capability, however, I would not have been able to keep the proper amount of pressure on my opponents when I was returning their serves, and on slow surfaces my power game would have be nullified by their passing shots. When circumstances dictated, I was able to give up the net game and come in only on short balls—just as Tilden and the others had done.

Though this trend seems to have been reversed, for a time many youngsters in this country wanted nothing else but to become whiz-bang serve-and-volley players. Many of them thought they were copying my power game, or that of Pancho Gonzalez, the big server who came along just after me and made a tremendous impact. Interesting, Pancho did gain his big amateur victories largely on the strength of this serve, but his game really didn’t become truly complete until he was forced to improve his groundstrokes after losing to me on tour, 27 matches to 96. I had been forced to give up my big serve in order to beat Bobby Riggs in a previous head-to-head tour—you learn a lot when you turn pro!

In any event, an awful lot of boys growing up in the 1950s and 1960s—encouraged by a fair number of  coaches who perhaps should have known better—learned to attack before they knew how to defend. Many never did learn solid baseline tactics and ended with incomplete, highly vulnerable tennis games.

As my experience with Riggs on our tour made me realize, there’s nothing aggressive about hitting big serve if your opponent can block it past you every time.

Too many young players have equated “defensive” with “weak” or “tentative”. There was certainly nothing tentative about the way Don Budge returned serve. He may have remained at the baseline, but he hit bullets back at you. And as we shall see, I recommend that beginners start hitting with topspin—the faster and potentially more aggressive ball spin on both forehands and backhands.

Anyway, the trend toward over-emphasizing serve-and-volley has been stopped at last. Jimmy Connors and Bjorn Borg are among numerous rising young stars in the game today who have demonstrated magnificent control from the baseline. For youngsters beginning in tennis now, these stars helped restore prestige to the groundstrokes. That is how it should be, and where we will begin."

Mr. Kramer’s last paragraph is especially prescient and telling, in light of how tennis at the pro level is played today by the current generation of (aggressive) baseline stars like Roger Federer and Rafael Nadal.

Earlier on pages 8 to 11 in a section titled “About Ball Spin,” Mr. Kramer offered this sage commentary about how crucial it is to master applying/generating spin on your strokes to becoming a successful competitive tennis player:

" Baseball rewards fair balls hit out of the playing area, so sluggers like Ted Williams or Hank Aaron never really had to worry about control over the balls they hit. But tennis penalizes shots that don’t land inside the baseline and sidelines. The secret to keeping shots within bounds in tennis is controlling the spin on the ball. So before we get into the actual mechanics of stroke execution, let’s look at spin briefly.

The flight of a tennis ball is controlled through a combination of gravity and spin. Gravity along won’t keep a ball in play. A serve hit firmly but without spin would not only miss the service box—it would go beyond the baseline. A groundstroke hit with any firmness would also go beyond the dimensions of the27-by-78-foot single court, before gravity brought it down to earth. A shot hit softly at an angle would still go outside the sidelines. A shot hit softly all the way from one baseline to the other baseline might stay in—but it wouldn’t pose much a problem for the other player.

In other words, spin must be imparted to the ball in some degree. A brushing or biting action of the racket strings during the interval of impact accomplishes this. I use the word “interval” to promote the idea of a prolonged period of contact between racket strings and ball, and not an instantaneous hit or slap.

Actually, Vic Braden—one of the game’s most innovative teachers and one of our most tenacious researchers in the technique of tennis—has taken high-speed photographs that reveal the racket strings hit the ball twice on every stroke. At the instant of contact the ball rebounds off the strings. Then the strings catch up with the ball and hit it again. While this may indicate a need to rework the “double-hit” rule in tennis (you’re not supposed to hit the ball twice), it is too finite as a physical phenomenon for our human senses to grasp fully. I think it’s important simply to imagine that the racket strings act upon the ball as a stiff bristle brush might. It is by “brushing” the ball for as long as possible that you are able to impart the degree of spin you need, for absolute control. Brush up on the ball with the racket strings—as you do when the path of the racket on the forward swing goes from a low to a high position—and you will produce topspin, or overspin. When a ball has topspin, it rapidly rotates end over end in the direction that the ball is moving. The shot flies in a half-moon trajectory over the net and drops sharply on the other side.

Brush down on the ball, and you will produce a shot with backspin, or underspin. When a ball rotates end over end in the opposite direction it is traveling, the shot clears the net more slowly and by a greater margin, and it drops more rapidly once it has reached its peak.

In these two examples, I have made the assumption that the racket itself is just about square during impact. By that I mean, the frame of the racket is perpendicular to the ground. So it is the path of the racket that creates the exact brushing action. But topspin or underspin can also be imparted by “closing” or “opening” the racket face during the interval of impact. That means tilting the frame of the racket toward the net or toward the back fence, as you stroke. On short strokes such as the volley or the lob, where underspin is desirable for control, or height is needed for defense, that’s what happens.

The important thing to note for now is that the brushing action, created by the path the racket face takes during the forward swing, or the alignment of the racket face at impact, or a combination of both, brings the two-ounce tennis ball under control. With spin, you can hit balls much harder and still keep them in the court. That’s what we’re after in groundstrokes and on the serve."

There are a few” take-homes” from these two particular passages from the mind of Jack Kramer that we would like you to take into the New Year:

Mastering baseline play –“defensive play”—remains the foundation of any successful competitive tennis player.

This reality is especially true in the current era of pro tennis where play is dominated by powerful groundstrokes from the baseline – a tactic that is supported and encouraged by slower court surfaces, heavier balls (rather, balls with thicker felt), and the development of racquet and string technologies that make it far simpler to generate the massive topspin necessary to maintain “absolute control” over those high-speed shots.

The mastery of ball spin remains as, arguably, THE critical skill in the repertoire of a successful competitive player, especially for players seeking “ultimate performance”.

While our understanding of how spin is generated becomes more sophisticated as high-speed photography/video becomes cheaper and therefore more accessible to those who are interested in those details, even Kramer recognized the fundamental ways – controlling the swing path and/or tilting the racket facing during the “interval of impact”—that spins are generated.

The difference between 1977 and now is that players are trying to strike their shots with far more pure power –ball speed –on their shots, and so they also have to generate far more topspin to maintain “absolute control” and keep their shots in play. It’s also fascinating to now observe that the today’s most successful—and most powerful – players appear to use/prefer/emphasize one particular (top-)spin generating method (on the forehand side) over others.

The reason(s) that would explain why this stroke mechanical “preference” among tennis’ top performers even exists  (beyond the oversimplified “because they work, silly” response) might be critical if we want to provide the best possible information to help future competitive players maximize their power –and control—potential.

Bottom line here is this:

I hope that you will now realize that any stroke mechanical concept that attempts to increase power without increasing (top)spin generation simultaneously is essentially a worthless concept.

In today’s tennis, if you're seeking maximum performance, these two performance/technical elements - power and spin - are for all intents and purposes, inseparable.

Let me end this post with these words from a former top player who used to spar frequently with the late, great Mr. Bill Tilden way back in the day.

Mr. Tilden’s advice to him:

“If you don’t learn topspin, you have no future in tennis…”

True that.

Happy New Year and TTFN!

 

A Roadmap to a Hall-of-Fame Forehand - Part 2: Does the Impact Location on the Stringbed Matter?

When we first started capturing high-speed video of the world’s top tennis players, one thing that we noticed right away is

1) how often the top players make contact with the ball in places other than the center of the racket face

and

2) how often and how much the racket twists and in the player’s hands rather than staying “stable”- i.e. no twisting – in the milliseconds after impact

particularly on groundstrokes struck with heavy topspin or underspin.

What we were seeing runs entirely against one of the most fundamental instructional mantras of tennis –the one that goes “hit every shot in the center of the racket”.

What was even more intriguing/surprising was that for some players, especially the ones who have been ranked #1 in the world or have multiple Grand Slam singles trophies to their names, very often make contact closer to one edge – especially the bottom edge – of their racket, especially on their topspin forehands.

What we have seen is that the top players make contact with the ball in one of three (3) fundamental locations on the stringbed on their groundstrokes.

The first impact location is in the upper part of the stringbed that’s closer to the top (or leading) edge of the racket:

The second impact location is in the “geometric” center of the stringbed:

And, the third impact location is in the lower part of the string bed near the bottom (or trailing edge) of the racket:

What you should also notice is what happens to the racket just milliseconds after the ball leaves the stringbed after making contact in each one of the three fundamental impact locations.

When impact occurs near the leading edge of the racket, the racket rotates to an open position (tilts backwards) with the strings pointed toward the sky.

When impact occurs in the center of the stringbed, the racket (face) remains very stable and remains in (more or less) the same orientation as it was before impact.

When impact occurs near the trailing edge of the racket, the racket rotates to a closed position (tilts forwards) with the hitting surface often ending up pointing directly at the ground.

When players make contact with the ball near the trailing edge of their racket on a topspin groundstroke – most commonly on a topspin forehand – the forces generated by the interaction of the ball, racket and strings at impact cause the racket to rotate suddenly in the player’s hand and results in the sudden forward tilt of the racket face.

Even the hand and forearm strength of a tennis champion cannot resist the forces created during the collision of the tennis ball with a racket that’s moving at speeds over 80 MPH that’s encountered during this type of off-center contact.

Now, what could possibly be the reason – the benefit – for making consistent, off-center contact with the ball?

After all, isn’t the ability to strike every shot in the center of the stringbed the very hallmark of a tennis champion?

The most common reason that has been tossed around by various tennis coaches over time is the anecdotal claim or belief that making off-center contact on forehands or backhands can increase the amount of spin generated – either topspin or underspin – on a given stroke.

We are not aware of any (published) direct evidence that supports this idea that off-center ball contact somehow influences – and more specifically, increases spin production in groundstrokes, so we decided to conduct a preliminary study to determine if there’s any relationship between impact location and topspin production.

In this preliminary study, we looked at high-speed video clips of the topspin forehands of the three (3) active players who have won two or more Grand Slam singles titles: Roger Federer, Rafael Nadal, and Novak Djokovic during tournament play and practice on hard courts.

Specifically, we measured the amount of topspin (in RPMs) generated and recorded the type of racket motion through the impact zone – whether or not the racket tilted forwards (to the ground) or backwards (to the sky), or remained entirely stable after impact for a minimum of 60 forehands (struck in a wide variety of situations/court positions) per player.


The table below summarizes what we found:

So, based on this very preliminary analysis of topspin production and racket motion in the impact zone, we conclude that:

The highest topspin rates (nearly 40% higher compared to “center contact”) are produced when impact occurs near the bottom edge of the racket;

AND

The lowest topspin rates are produced when impact occurs near the top edge of the racket.

So, when you see this sequence of images when Roger strikes his forehand, you now know that he is producing much more topspin with his "twisting" racket compared to making contact with a “stable” racket in the impact zone:

We’ll begin exploring the reason(s) why these different topspin rates are related to the impact location on the stringbed, and how these great champions are able to “manipulate” contact on the court during live play…

As well as compare topspin production versus impact location in other, non-current or previous World #1s or non-multiple Grand Slam-winning tennis players in future posts.

So stay tuned.

TTFN!

A Roadmap to a Hall-of-Fame Forehand - Part 1: What is the Racket Really Doing in the Impact Zone?

Last time, we left you with this image showing you the positions of the racket face and the shape of the racket path during the forward swing to impact that are used by arguably the best two forehands in tennis today:

Now, let’s begin drilling down into what you can learn about these two “strokes of genius” (as well as some the other great forehands of recent years – like the cannon demonstrated by the Chilean great, Fernando Gonzalez) help you create your own “SlamMaker” forehand that enables you to maximize both ball speed –“power”—and topspin—“control”.

A really good place to start drilling down into the forehand mechanics used by today’s top players by taking a closer look at what the racket face is doing in the “Impact Zone” of the stroke – i.e. what the racket does in the 3 feet before impact, at impact, and 3 feet after impact.

This is not to say that there aren’t other factors—grip, shape and size of the backswing, the size and shape of the follow-through, etc.—that strongly influence the speed, spin, trajectory and placement of the resulting shot. We just need to start somewhere, and in our opinion, that place is to really look carefully - mindful of any lurking "inattentional blindness" issues that are always lurking about (remember the moon-walking bear in our last post?)- at the most fundamental interaction of the racket, strings and ball which happens in the moments before and after impact.

I Can See Clearly Now...

First, let’s discuss some important background information that is necessary to understand the context of our findings regarding the “behavior” of the racket before, during and after impact. In general, I would say we are heading into somewhat uncharted waters because first, and foremost, it wasn’t really practical to even undertake this type of research and analysis because the necessary tool required to even gather the needed information to resolve clearly what rackets and balls are doing in the 3 feet before and after impact was simply too expensive to access.

Before 2008, the high-speed video technology need to see clearly what’s going on in the 35 to 40 milliseconds it takes a top player to move the racket the 6 to 8 feet of their Impact Zone was limited to the military and industrial-grade high speed video systems- capable of incredible frames rates in the 100,000-plus frames per second (“fps”) range to study, for example the initial trajectory and spin rates of bullets fired from guns. And, the pricing for this technology generated started in the 10s of thousands of dollars.

So, the fantastic costs involved in making even the most basic high-speed video study of tennis motion naturally proved a significant roadblock to overcome.

A few sport science researchers bit the bullet and bought or borrowed high-speed video equipment to dissect the intricate details of athletic movement and performance, and tennis has had its share of high-speed video-based research in the past 40 years. Western European and East Bloc countries started performing high-speed video studies of their elite tennis players starting in the early 1970s, and folks like Vic Braden and Gideon Ariel started filming tennis motion using high-speed cameras at about the same time in the US.

Truth or Beauty – How informative are your favorite instructional videos?

So, the great majority of the high-speed video footage, until John Yandell started the Advanced Tennis Research project in the late 1990s, was taken of the sport as it was performed in the 1970s. Yandell should be given all due credit for taking the initiative to pay the steep price and start taking high-speed footage of the current top players.

The limitation of the Advanced Tennis and now, TennisPlayer footage, however visually stunning, is that a lot of that footage is not usable from an analytical, quantitative perspective. Mainly, through no fault of their own—as he and his team did not have much control over where they could place their cameras in various stadiums in the US and Canada—the camera angles and perspectives of their footage deliver mainly qualitative information.

Therefore, the great majority of TennisPlayer articles cannot go too far beyond descriptions of what they see on the videos, and while they do see much more detail using high-speed cameras, the authors on that site do not have the necessary, integrated background in the knowledge areas – anatomy, physiology, physics, neurobiology, biomechanics, etc. – to clearly explain why certain moves are made, what the results of the moves are for different players at different levels, etc. Mainly, the articles tend to cherry-pick the footage that justifies long-standing instructional ideas, concepts and methods.

More recently, the introduction of Exilim High-Speed camera line by Casio, starting with the Exilim EX-F1 in 2008, puts what is essentially a “sports motion microscope” into anyone’s hands. But, as with anything, it’s not the “data” itself that is most valuable, it’s making sense and meaning from those data that truly matters.

With that said, here is what you need to begin to understand about what’s going on in the impact zone of a top player’s forehand by looking directly at how they themselves move their rackets though the Impact Zone.

Three Questions Every Player Should Ask Themselves...

Let’s start with three very basic questions:

What is the racket doing in the Impact Zone?

What is the position of the racket face before/during/after impact?

What variation in racket motion exists as it moves in the Impact Zone?

Oh yes, there’s one more important detail I would like to mention before we start attempting to answer these three questions. Given the reality when players compete in live matches, we need to understand that the unpredictable nature of match play forces players to adapt their stroke mechanics to the highly variable situations that emerge during live play. Therefore, to reduce the higher levels of variation in the stroke mechanics – the body and racket motion – that is inherent to competitive play, we will try to limit our analysis to the strokes players used in their (cooperative) warmup before training sessions or in their in their pre-match warm-ups during tournaments.

In this situation, they encounter far less variation as they execute their strokes mostly down the middle of the court (you know how you would feel if your partner were jerking you around the court instead of keeping the ball in the middle during the warmup!), so this enables us to witness what effectively is their “base mechanics”, or most fundamental stroke mechanics.

Then, from these “base” mechanics, the player will then adapt these mechanics (adjusting speed, spin, trajectory, direction, etc.) to the highly variable challenges they face during live competition.

How Much Can Really Happen in 30 Milliseconds Anyway?

So, let’s take a closer look at what Federer and Nadal achieve in the Impact Zone of their forehands:

With the help of our video analysis software of choice, V1 Pro, we marked the position of the racket face as it moves through the Impact Zone using the following convention:

Yellow lines mark the racket face position before impact,

A green line marks the position at impact, and

Red lines mark the positions after impact.

As the video was captured at a speed of 210 fps, the time that elapsed between each line is 1/210 or 0.0048 seconds or 4.8 milliseconds.

We traced the position of the racket face starting 5 or 6 frames or 4.8 X 5 frames/ 4.8 X 6 frames = 24 milliseconds to 28.8 milliseconds before and after impact. We also estimated the angle of the racket face at different stages of their stroke: i.e. 1 frame before impact, at impact, and sometimes, 1 frame after impact and at the stage in their follow-through when their racket arm reaches shoulder level.

Now, let’s start really drilling down on the first two questions we posed: what is the racket face doing in the impact zone and what is the position of the racket face before, during and after impact?

Here’s a close-up of the trace of the racket motion of each future HOF’s forehand in the impact zone:

The first thing you should notice is that both players tilt the racket forward throughout the impact zone – i.e. the racket face is closed at every millisecond in the impact zone. Not open — tilted upward toward the sky— nor square or vertical — where the racket face is oriented perpendicular to the court — but closed at all points in the impact zone, even at impact.

This observation alone should bring to a conclusion a long-standing debate about how players today produce topspin on a forehand. This image alone shows conclusively that players do indeed tilt the racket forward when they execute a topspin forehand, and the racket face remains tilted forward at impact, often at an angle that is much farther forward that had been previously thought possible.

At impact for the forehands shown here, Federer’s racket face is tilted forward 11 degrees at impact and Nadal’s racket face is tilted forward 15 degrees (relative to a perfectly vertical racket face.

And the racket path used by each player for the same forehand as shown above is interestingly the same: the racket for both Federer and Nadal are moving 18 degrees upward…

Both elements – the forward tilting of the racket face, and an upward – or “low to high” – swing path are used by these HOFs to create contact to produce a shot that commonly leaves the racket at ball speed over 80 MPH and topspin rates upwards of 3,000 RPM.

Now, while these observations very much sound like "old hat", when we started to look deeper into the usefulness and validity of the age-old topspin mantra of "swing low-to-high with a vertical racket face", we found an interesting disconnection between the "theory and reality" of topspin production.

Does "Theory" Really Match the "Reality" of Topspin Production?

In an ideal world, whenever people make a sound, thorough and objective analysis of any subject, the "theory" and "reality" should match one-to-one.

Given what we observed about how Federer and Nadal really move their rackets through the Impact Zone on their respective forehands, we conclude that there seems to be a gap between "theory" and "reality" when it comes to understanding how massive topspin is generated by today's top players.

When we tried to look for more information on the subject of topspin production on tennis groundstrokes, what we found was that this type of really fundamental information about racket motion in the Impact Zone is not widely known or studied, much less published. We eventually found a few coaches and researchers offering some tidbits here and there from their work, much of which is very hard to access, even with the Internet.

We found that there are two "schools of thought" about the "theory" behind topspin production on groundstrokes (based on published works in English).

The first "school of thought" behind topspin production - "get the racket below the ball then swing up on the ball steeply from low-to-high with a vertical racket face" - is best described in a 2001 article by Vic Braden in the late Eugene Scott’s “insider magazine”, Tennis Week.

In the article titled: “Top Ten Tennis Myths – Myth 3: Rolling the Racket Over the Ball for Topspin” (published February 13, 2001), Braden wrote this:

“A highly debated issue, at the moment, is the position of the racquet face when it impacts the ball. On a typical groundstroke, a vertically positioned racquet at impact, when the racquet was traveling upwards at approximately 17 degrees, produced no topspin. Therefore the racquet must be traveling at rather severe upward angles to generate the desired topspin. The exaggerated example is when players want to generate excess topspin to hit short angled passing shots, they often swing close to 90 degrees upwards and finish the follow-through over their hitting shoulder. We have digitized some shots where the racquet face is pointing downwards five (5) degrees. We have seen a racquet face pointing downwards nearly twenty (20) degrees on a half-volley when the incident angle is severe and the player is trying to keep the ball close to the net tape. However, we have film on several top players and their racquet face is normally vertical when impacting the ball on groundstrokes, even the big time topspinners.” (page 34)

The second "school of thought" behind topspin production on groundstrokes -where topspin production is the result of striking the ball with a racket face that's tilted forward - is best summarized on pages 131 to 135 in the 2005 book “Technical Tennis—Racket, Strings, Balls, Courts, Spin and Bounce” by Rod Cross and Crawford Lindsey.

There, in “Match Point Box 4.3” on pages 134, they mention that an analysis of a midcourt topspin forehand struck by Federer showed that Fed’s racket face was tilted 8 degrees forward at contact and the racket was moving upward at a 30 degree angle. Based on these observations, Cross and Lindsey rightly concluded that after seeing the racket motion of Federer’s racket using high-speed video (at “only” 125 fps) that concluded that Braden’s view needs at the very least, to be re-visited:

“For example, many coaches still believe that the racquet face must be vertical to hit a topspin forehand or backhand. However, Roger Federer and many other players tilt the racquet forwards, especially on balls hit above the waist. Sometimes the ball is not struck in the middle of the strings but lower down near the frame. As a result, the racquet head rotates during the shot so that the head is tilted forward by the time the ball leaves the strings.” (page 135)

Later, on pages 137 to 139, Cross and Lindsey present a more detailed explanation of topspin generation, and even provide a schematic (Figure 4.10 on page 138) showing what happens as a result of varying the racket path angle and racket tilt on topspin generation.

But, like many “laboratory - ” or “thought experiments”, when we started looking at these questions ourselves, we find quite different results when it comes to topspin generation during live play (we’ll discuss this much more complex topic in a later post).

Time to Revisit the How-To Behind Generating Topspin?

Clearly, even our somewhat simplistic look at racket position and motion in the impact zone shows that, from a coaching perspective, Braden’s view of the vertical racket face plus low-to-high, upward swing path being the primary mechanism behind topspin production on a forehand isn’t correct.

The spin rate of the Federer forehand shown was 2,300 RPM and the spin rate of the Nadal forehand was nearly 2,600 RPM, and such enormous spin rates are hard to reconcile with Braden’s 2001 view of topspin production for the forehand. Both Federer and Nadal have their rackets tilted forwards more than double the amount—in this case, 11 and 15 degrees forwards compared with the 5 degrees forward tilt Braden and his colleagues found among players up until early 2001), and the overall path of racket motion was exactly the same as — 17 degrees upwards — as the racket path that Braden and his colleagues showed produced 0 RPM - no topspin whatsoever - albeit under laboratory conditions, if I remember correctly.

Clearly, this difference between “theory” (at least whatever was Braden’s view of how topspin is generated) and “reality” means that we need to be taking a much closer look at what factors are necessary to generate the ultra-heavy spins we are seeing today…

And, I can tell you that it’s not solely the result of the “modern equipment” and the higher swing speeds used by today’s players.

When we look most of the bigger forehands used on tour today, we see exactly the forward tilt of the racket face at impact and throughout the Impact Zone (with certain exceptions—which we’ll also discuss somewhere in the not-too-distant future, I hope) and a relatively shallow (generally less than 20-22 degrees upward - which is nearly 30% shallower than the path shown in Cross and Lindsey's Federer analysis) rather than steep upward racket path.

First up, let's look at the racket motion in the Impact Zone and the angle of the racket face at impact (itself) for Fernando Gonzalez and Nicolas Almagro…

Next up, here are Kei Nishikori and Fernando Verdasco…
(Hey, maybe if you want to develop a monster forehand, you might also consider changing your name to Fernando?)

Now, here are Marat Safin and Andy Roddick...

And to close these proceedings, here are Novak Djokovic and Tomas Berdych...

Maybe, what we need to take home from these observations is that these—now visible, due to greater access to high-speed video—differences in racket motion in the Impact Zone used by this generation of top players are the core “innovation” or “evolution” of forehand mechanics—driven by player ingenuity, if not “player genius”—between 2001 and today. Certainly, the ability to generate much higher amounts of topspin is absolutely necessary maintain both control and precision given the higher racket speeds and ball speeds sought by today's ATP competitors, in general.

Cross and Lindsey at least recognized in 2005 that certain players were clearly creating racket motion using their forehand mechanics that were significantly different from the “classic models” and "theories" like those championed by folks like Braden, Lansdorp and literally just about everybody else.

Now it’s 2011, and our initial analysis of the racket motion through the impact zone, combined with our measurements of spin rates of the top forehands on tour shows that, at this point in history, the huge gulf between existing “theory” and “reality” of topspin generation means that we still have quite a ways to go before we actually have a solid understanding of how racket motion through the impact zone and racket tilt actually influence topspin production.

Now, when you then realize that the vast majority of tennis coaches, instructors and internet gurus still push the classical topspin mantra of "get the racket well below the ball, keep the racket vertical and swing low-to-high, and brush up on the ball", can you really expect them to help you develop a topspin forehand that performs like your favorite pro player?

So, how do you apply what we’ve discussed here to your forehand?

First, you have to get your head around this “novel” method of generating topspin…

Because if your brain doesn’t understand what it is you’re trying to achieve, you’re stuck until you get to that point where you “can wrap your head around” the ideas and concepts needed to achieve the forehand mechanics of today’s top players.

The first step is to forget the claasical, “keep the racket vertical and swing low-to-high steeply” advice that many of you have been hard-wired into your tennis brain and begin thinking and doing the opposite:

Which is…

Shut the racket face down throughout the entire stroke and shallow out your overall racket path, especially in the impact zone.

Further details of how to achieve this type of racket motion at the racket speeds needed to produce the identical results as players like Federer and Nadal are going to fill a lot of future blog posts, folks.

And one last thing...

Sorry, But The (True High-Performance) Menu Is Not Big...

And contrary to another false paradigm of tennis instruction: if you start to look carefully at what those players on TV are really doing, it becomes clearer that there is really only a very specific set of movements that can be used, arguably only one way to achieve the same forehand mechanics, and therefore the same forehand spin and speed performance of Federer and Nadal and other ATP stars.

The naked eye cannot see—no matter what your coach, Internet guru or park instructor says or writes—cannot distinguish the “micromotion” that defines today’s HOF forehand. As no two humans are built the same, any two forehands will “look” different to the naked eye. But from a more objective perspective, the stark reality is that there is only a very limited and defined set of movements that must be made in a certain sequence to produce a SlamMaker forehand.

TTFN!

Forehand Speed and Spin Rates of the ATP Stars

For those of you arrived here after clicking the link from our YouTube channel to find out what the exact spin rates are for the 4 forehands and 1 backhand shown on the Federer video clip…

Here are Fed’s spin rates to the nearest 100 RPMs without further ado:

Forehand #1: 700 RPM

Forehand #2: 2,500 RPM

Forehand #3: 800 RPM

Forehand #4: 3,100 RPM

Backhand #1: 1,800 RPM

The wide variation in the amount of topspin that Federer can generate on his forehand - a 2,400 RPM variation among the 4 forehands shown on the video - is but one of his many remarkable abilities that he has tapped on the way to 16 Grand Slam singles titles.

How he does this, we will discuss in future posts...

Now, if you are curious about BOTH the ball speed AND spin rates for the top ATP players on the forehand, that information – obtained using our own high-speed video footage and custom video analysis software—is listed in the table below.

*The average ball speed and spin rates shown here were measured for forehands struck at “rally speeds” used by the respective players on hard courts in 2009 and 2010.

So, how do top player ball speed and spin values compare to players at other levels?

We’ll eventually present those numbers for college and junior players, and to give you a preview, the difference in forehand speeds and spin is very similar to the differences in serve speed—often 30% or more—we presented in earlier blog posts: (http://www.tennisspeed.com/blogs/2007/07/informal-serve-speed-survey-of-us.html).

Finally, if you watch the Federer video clip very carefully, you might notice something interesting about the way Federer makes contact on the two high-spin forehands on the clip – forehand #2 and forehand #4 – compared to the two lower-spin forehands – forehands #1 and #3…

What’s so interesting about the apparently subtle differences in contact between those forehands?

Well, let me give you a hint…

It has something –well, everything, actually – to do with the question we posed in our last blog post, “The 500 Million Dollar (and Counting) Question of Tennis”.

We’ll start looking at the answer to the “500 million Dollar Question” next time.

TTFN!

The Power Revolution in Tennis - Part 3 (Behind the scenes of the Federer Forehand)

The last post in this series – The Power Revolution in Tennis – Part 2 (Defining the New Topspin) – I focused on the two main fundamentals of the “New Topspin” that’s employed by the stars of the sport today on the signature shot of power tennis – the power forehand. The first of these “modern fundamentals” is the closure of the racket face during all the phases of the stroke, and the second is the shallower overall swing path that enables today’s players to create a flatter, more penetrating shot trajectory without affecting their ability to generate sufficient topspin to maximize control over their shots.

No one player has leveraged these two crucial elements of the modern topspin forehand more than the 12-time Grand Slam singles champion who goes by the name of Roger Federer.

In this post, let’s take what’s perhaps a bit of a sideways journey into learning more about the story behind the development of what’s essentially the state of the art in tennis forehands these days, the Federer forehand.

The “greatness” of the Roger Federer forehand is nothing particularly novel from a technical standpoint. IMHO, the Federer forehand is not a “novel synthesis” of “classical and modern technical elements” as some want to interpret it (see Tennis Magazine – US, May 2008).

Arguably, every player’s stroke technique is essentially a synthesis of certain specific ideas, philosophies and movements. Did Roger come up with his personal synthesis on his own?

Not really. You’ve got to give credit where credit is due. Roger had help. (To find out who helped him develop his signature forehand, read on!)

Federer’s forehand represents a integration of technical elements from 3 particular former Grand Slam champions (who themselves won a total of 27 Grand Slam singles championships) to create the forehand he’s employed only since mid-2001, around the time he bounced one of his tennis idols, Pete Sampras from Wimbledon in a compelling 5-set clash at Wimbledon.

Before I reveal the “ancestral lineage” of the Federer forehand, it is interesting to note that it took Roger almost 3 years (maybe longer) to develop and employ the forehand the fans have come to revere and his peers have come to fear, envy and revile. If you have ever seen footage of Federer before 2001, you would have seen a very different forehand entirely. Roger’s forehand when he broke through at the Grand Slam level in the juniors (1998) and in his first 3 years as a pro (1998-2000) resembled the old Sampras forehand more than the one that’s driven him to 12 Grand Slam titles in a little over 5 calendar years.

Search for a YouTube video of a 1998 indoor match between Federer and Andre Agassi played in Roger’s hometown Basel Indoors, and you’d see a fast, but much flatter, and unpredictable forehand that Federer would execute by fanning the racket face open in the backswing and then closed as he accelerated to contact (a la Sampras in his early days on tour). When he “timed” the closure of the racket face correctly, the result was devastating. However, the reality was that for every sweet stroke that blasted past Andre, Roger would mistime the closing of the racket face 3 or 4 times and create shanks that handed Andre a ton of free points over the course of a two set defeat.

Basically, credit is due to Peter Lundgren, Roger’s original “sherpa” on the pro tour for helping him learn the skills to transition his classic, “Samprasian” flat forehand into the “SlamMaker” version of the past 5 years. What Lundgren was able to accomplish between 1996 and 2003 was to add the necessary modern refinements to Federer’s original Sampras-Becker-style forehand technique to increase the overall safety and consistency of his stroke.

Once Federer mastered the fundamentals of the modern Swedish topspin forehand, the rest, as they say, is history.

For you technical afficiandos, if you look carefully, and have a very good visual memory – Roger’s forehand today bears more than a close resemblance to the forehand stroke used by Mats Wilander during his salad days where he won 7 Grand Slam singles in a 6.5 year period between 1982 and 1988. Federer makes bigger movements than Wilander did – i.e. Roger makes a much larger rotation of his upper body and has much greater extension of his racket arm through the contact zone than Mats, but the general swing shape and underlying “philosophy” (maximum topspin to maximize safety and consistency) is essentially the same.

Until Federer mastered the principles of the Swedish-flavored, modern heavy topspin forehand: closed face at all points of the swing, combined with the powerful forearm rotation through the contact zone (the so-called “wiper”), his forehand was more of a liability than the “SlamMaker” we know today. Roger has always had the racket speed that few players in any generation possess, what he lacked until say, the end of 2001 to early 2002 was the ability to harness and control his natural racket explosiveness using the only practical means to harness and control that kind of power: the application of massive amounts of topspin… As well as express his natural “creativity” for varying his strokes by being able to more reliably control his ability to generate (top-)spin for every stroke.

From a technical standpoint, the “SlamMaker” has evolved from the techniques he originally adopted from his early tennis idols, Boris Becker (6 Slams) and Pete Sampras (14 Slams), combined with the Swedish refinements (based on the Wilander forehand which helped him win 7 Slams) set into place by Peter Lundgren. Do I have any knowledge of exactly when Lundgren began the work that eventually led to the emergence of the SlamMaker? No, I really don’t…

All I really know is that without the topspin maximization techniques brought by Lundgren, it’s pretty clear that the history and landscape of pro tennis over the past 5 years would be starkly different. Without the emergence of the SlamMaker, Lleyton Hewitt probably would have won close to 10 Slams himself by now and we’d be talking about the Hewitt-Nadal rivalry or era.

The only technical element that might represent a true “innovation” by Roger is his tendency to “break” the so-called “double-bend” or “double-confusion” (as my friend coined it) structure that the US teaching pro establishment has come to espouse as a so-called “modern stroke fundamental”.

The true function of this movement - breaking the “double bend” structure of his upper arm and forearm through the contact zone -is to enable Roger to fully release the stored energy – in the form of higher racket speed – he originally created by arranging his arms the way he does in his backswing.

If Federer were to retain the “double bend” structure through the contact zone, and then execute the “wiper” finish, he wouldn’t be able to use the natural acceleration and energy that results from allowing the forearm to accelerate and extend forward.

Effectively, the Federer forehand is a modified sidearm throwing movement that resembles that movement that’s used by a major league infielder when attempting to throw out a speedy runner on a ground ball. In order to get any kind of velocity on that sidearm throw across the diamond, the infielder must “break” the arm angles he created initially after picking up the grounder, and create the same arm “extension” as he releases the ball from his hand.

That “extension” of the arm at the release point of a throw or through the contact zone of a tennis forehand is critical for maximizing velocity (and spin, if you have the “closed face at all points of the stroke” part already down cold). Did Roger consciously "invent" this movement? I personally kinda doubt that. As far as I can tell, Roger's not the first to employ this type of movement as a part of his forehand. If you look closely at tennis techniques in the history of the sport, there have been other top players who used the same move (i.e. remember Jimmy Arias?).

So, what does that tell you about all those tennis players who are/were trained to maintain or “hold on” to the double-bend structure? What it tells me is that there are a lot of players out there who have the potential to really improve their forehands. What does that say about the coaches and pros who “trained” these players in the revered “double bend” technique?

Hey, draw your own conclusion about that…

TTFN!