This page is about racket sports and how to improve at them. But in a sense it also has something to do with data science and simulation science. S3's founders are active in racket sports communities at the local and national level. We believe these sports are a good way to keep the body and mind fit; a prerequisite for doing good science by the way. And our perspective on improving at racket sports is based on modeling. Some would say it's about developing a "system" that works, but there's scarce little difference between a model and a system in that sense.

We've worked with some of the most respected racket sports players and teachers in the world. In addition, we sponsor tournaments, host youth programs, and do a great deal of work to train up-and-coming players in various sports. We think that--coming from technical backgrounds--we have a fairly unique perspective and can make a significant contribution to the way these sports are taught. So this part of our web site is a resource for people who want to play better racket sports. Our goal is to develop: 

  • A model of player performance: How to evaluate the level of an opponent, or, more importantly, how to self-evaluate your own level. 
  • A model of player improvement: How, starting with your assessment of yourself as a player, you can get better.

When S3 founder Jamie Lawson was in his late teens, one of his racquetball partners was Jimmy Doyle, a world's top 20 player at the time (they still play together, more than 40 years later). Racquetball was booming back then, and there were lots of books on the sport coming out at the time. Too many to read all of them. Jamie asked Doyle what he thought the best racquetball books were. Doyle told him: "In my opinion, the best racquetball book is Timothy Gallwey's The Inner Game of Tennis". Puzzled, Jamie asked "how can a tennis book help racquetball players?" "Outside of some mechanical differences," Doyle answered, "most racket sports are pretty similar. Certain athletes may excel at one sport or another, but the concepts that must be mastered are much the same." Our discussion here is an attempt to enumerate and understand those common concepts, and we think that by making the discussion independent of any particular racket sport, it's easier to focus on the bigger picture, and improve at how to play your sport. A general theme in our approach to improvement is to work on the weak spots, and a supporting theme is to use the strong spots to improve the weak spots. This seems like an obvious approach, but often, players follow Molly Ivans' rule of "dance with them what brung ya", They think, "I worked on my cardio and it got me to this level, so I'll do more cardio". But champions are always working on different stuff. A reality of two-player or multi-player games is that the opponent will seldom play into your strength, and will usually look for your weak spot and try to exploit it. So whatever the short poles in the tent are, figure out how to make them longer. But just as important is to realize that there are more poles in the tent than those you can see. This is a good reason to work with more than one teacher. Each of them will show you different tent poles. But there are always pieces of the game you're missing. And you may lose because someone else recognizes those parts of the game. Working the referee is a good example. Lots of players see the referee as a bystander who won't be manipulated by the players. That's not how real matches work. In his autobiography Open, Andre Agassi describes one of his first tournament finals, as a junior, where the rule was that if you didn't have a referee, you call balls on your side of the court in or out, and those calls cannot be challenged. At match point, where the winner of the point would win the whole tournament, he hit a ball that was in the court by several feet and therefore unquestionably in. But his opponent, understanding this part of the game better than Andre, simply called the ball out and collected the championship to the boos of the fans. That doesn't mean you should call balls out just to benefit your score, but instead maybe demand a line judge at the start of the match to remove that tool from the opponent's arsenal.

Blair: The Model Player

Let's begin with a typical pattern that players go through in the course of their improvement. We'll call our player Blair. Blair could be male or female, it doesn't matter. One day, a friend invites Blair onto the the court and goes over the rules. At this point, the rules are the game. They play a few games. Blair has fun, but doesn't win anything, and feels kind of lost on the court. It's like a wilderness adventure hike and Blair has no idea where it's going. After the first three or four outings, Blair finally strikes a victory, and feels more at home on the court, without as much need to look down at the lines to get a location fix. At this point, the court is the game. Blair starts playing other hackers. Blair beats some of them consistently and loses to some of them consistently. Blair starts practicing more, and in order to turn some of those losses into wins, maybe buys a better racket and better shoes. At this point the equipment is the game. Suddenly, Blair's on the contacts lists of most of the hackers at the club, and some improvement results from regular play. But not long into this, Blair reaches the first plateau, and improvement slows to a crawl. 

Blair doesn't really know how to get off the plateau. Lessons might help, but what is a teacher going to do except say "get out and practice"? Not only that, taking lessons is like giving in and admitting that you can't do it on your own. But Blair has noticed that the better players are typically in pretty good shape. And they have to be to get away with wearing some of those spandex sports outfits. Blair has walked passed the gym a hundred times now between the locker room and the courts. But one day Blair makes that left turn and goes into the gym. With a modicum of commitment and a couple months work, Blair's bench press and squat maxes are up about 40%. Blair steps lighter on the scale now, and Blair's checking account is also about a thousand dollars lighter on account of all the new spandex workout clothes. About this time, Blair's game is also seeing a bit of a bump. Blair feels a little less depleted after an hour of play, and has started to take home some additional victories. At this point, the game is an athletic event. And Blair's name is now on the contact lists of some of the players on the club's intermediate ladder. But Blair consistently loses to them, and it's starting to feel like another plateau. 

It's time! Blair makes a call to the club's teaching pro, whom Blair refers to respectfully as "Coach". They hit the ball around for a bit and the teaching pro raises a racket and says "okay, I see what the problem is here. It's in your technique, your mechanics." The teaching pro--seeming to be a font of knowledge--sets Blair's feet and guides Blair's arms through the swing. "The correct swing," says our muse, like a character from Alice in Wonderland, "has definitive starting points and ending points, and definitive points in between. start 'here', then go to 'here', 'here', 'here', 'here', and finish 'here'". At this point, the game is the swing. And it is as complex as a fine wine. Blair practices the mechanics relentlessly, and is sometimes queried by the hackers on such stuff as "which grip to use for which shot?" But Blair is still getting beat in Podunk hit-around tournaments, and by players who aren't even changing out of their warmups, which is good because they'd be a sight to be seen if they tried to fit into spandex workout clothes. That's disappointing!

It's another plateau, but all is not lost. After an emotionally crushing defeat to a player with an inferior swing, Blair collapses just off-court, and an old codger hobbles over, taps a crooked stick on Blair's shoulder and says, "you know, with that forehand, I wouldn't lose a rally." Blair recognizes the old codger from pictures on the clubhouse wall; pictures of a better day when justice ruled and giants walked the earth. "I thought your swing would be...you know...perfect", Blair replies. And then the old codger looks Blair in the eye and says: "That's the thing, it's not about the swing!" Puzzled, Blair says "I'm confused". And the old codger says: "Well, if you want to understand, see me here at 7AM tomorrow."

So 7AM comes and Blair arrives to a frightening sight: the Pantheon. This is Blair's "Kung Fu Panda moment", you know, the one where Po realizes that he will be training under the direction of Master Shifu, with the Furious Five: Mantis, Monkey, Viper, Tigris, and Crane. Blair has seen them before, but only at tournaments where viewing was hard because it was standing room only. After a great deal of clubhouse talk and jabber, they finally get to play. At the end, Master Shifu closes with a question: "All of your shots were better than any of mine, and yet I won all of the rallies. How do you explain that?" This is the moment Blair realizes that the teaching pro taught by telling, and Master Shifu teaches by asking questions. This is also the moment that Blair finally realizes the difference between a teaching pro and a Coach. 

Blair spends many days and many nights searching for an answer to Master Shifu's question. Finally, in a dark dream it comes to Blair, and the next morning Blair greets Master Shifu at the club and says: "Coach Shifu. I have an answer to your question." Master Shifu waits anxiously for the answer and Blair continues: "It's not about the swing!" Master Shifu smiles approvingly. At this point, the game is about tactics: how to move the opponent to create opportunities; how to confuse the opponent with deceptions; how to use the entire volume of the court as a creative space. At this point, Blair also realizes that the most important place at the club is not the court and it's not the gym, it's the clubhouse where Blair and the Furious Five hold discussions on these important matters. Without the clubhouse, the club is just a place to play.

Blair occasionally takes a game from some of the Furious Five, but every time he plays one of them Blair's palms sweat. Blair tightens up and misses a lot, feeling exhausted even before they play. Crane lets the secret out: "It's how it is in life," says Crane. "So long as I'm more comfortable with the stress than you are, I will win." This is an epiphany for Blair. At this point, the game is the competition. It's how each of the players deals with stress. And Blair works on personal realization, on brushing off stress and just playing the game. Finally, one day, at the end of the match Master Shifu stands defeated. "How did you do that?" Master Shifu asks. "I don't know," says Blair. "I had a bunch of difficult situations, and in each of them, I saw the shot I wanted to hit and new I could make it." Master Shifu smiles, and says "now you know how to play!" At this point, Blair trades in the spandex workout wear for a crooked stick.


He or she shows you the "correct" starting point, the "correct" finish point, and places your arms at four positions in between: "start here, then move to here, here, here, here, and finish here." We'll refer to the example as "start, here, here, here, here, finish" or names like it. 

  they go into the gym and their play improves to a point and then they plateau. This plateau is also where players first consider the use of supplements including anabolic steroids. But they remain on the plateau because strength wasn't the problem. Then they seek out a coach who notices a lack of attention to technique and so the coach works on technique, and the player sees success, but moves to another plateau. Often, at that point, the player quits in frustration, or seeks out another coach or mentor, typically and older or wiser mentor to guide them on their game. Then the player again sees success but reaches another plateau. One takeaway from this is that while a player may reach multiple plateaus in their journey, the plateaus are different. They come about for different reasons and they require different tools to overcome. Eventually the player reaches age-limiting plateaus, where they have technique, game, competitiveness and even confidence, but basic biology imposes a reduction in their athleticism. These players can be the most instructional for young players to watch because their games are distilled down to just the parts the younger players need to build. At the time of this writing, John McEnroe presents a great example. McEnroe's athleticism has faded, and the varnish is even peeling on his technique--no doubt giving in to the problems of older joints. But at the tactical level, he still has an effective approach and his angles allow him to prevail against highly skilled players a half or a third his age. 

We begin here with some technical concepts that we think can help players improve. To illustrate these, we'll use a hypothetical example. Let's say that your coach 
Looking at the "start, here, here, here, here, finish" example, you probably shouldn't think of your teacher's detailed instruction as the "perfect" swing. Instead, think of it as an example of a swing, one you can use to help train to have a better swing. One of the things we do in science is to abstract from examples. That is, we develop general patterns or models that explain many examples. As we've already made clear, models are important to us as scientists, and models are also important to players so that they can build cohesive play. And we are always looking for models at higher and higher levels of abstraction, because higher levels of abstraction are more general, meaning that the models explain more examples. 

It turns out that abstraction is important in racket sports as well. So if you let the details of "start, here, here, here, here, finish" dominate your conceptualization of proper swing mechanics, it will do more harm than good. Recognize that in match play, you will seldom be able to achieve those positions. All racket sports are "games of emergency" as Peter Burwash says. In fact, another way to think about your coach's example swing is that this set of positions is what you want to prevent your opponent from achieving. That's what creates the emergency for your opponent. And your opponent will certainly do his or her best to create that emergency for you. Drill with those positions in mind. But once you are able to produce a swing, in practice, that flows through all of those positions (more or less), try to find the right abstractions that explain what those positions were trying to achieve. Instead of "your hand should be here and your racket should be here", it may be "the face of the racket should strike the ball flat, and the inertia should drive the ball toward the target". That's one level of abstraction. After we master it, we can look toward higher levels of abstraction, like, "the proper swing produces a ball that moves with sufficient pace and within a certain margin of error of the desired flight path". This abstraction applies to any ball, not just the one that you have ample opportunity to setup for and which allows you to flow through each of those six prescribed positions. So maybe you're on the run and the ball is fast moving away from you, and "start, here, here, here, here, finish" is simply not possible. But it is likely still possible to think about how to balance your swing to hit with sufficient pace, within a certain margin of locational error. At a still higher level of abstraction, you might conceptualize that "the proper swing produces a ball that creates an emergency for your opponent". Being able to hit with sufficient pace and accuracy may be how you create that emergency, but the real goal is not to hit with pace and accuracy, but to create the emergency. 

Players often talk about "going up a level" in their games. On the surface, they think of the levels as numbers, like going from a 3.5 player to a 4.0 player. And that's a reasonable way to measure competence, but more often than not, what the player is actually doing as they are moving up is reaching a higher level of abstraction in their game. So the real goal as you seek improvement is not to repeat the "start, here, here, here, here, finish" routine, but to master ever higher levels of abstraction of what "start, here, here, here, here, finish" really means. To be sure, you should not always try to think at the highest level of abstraction. If your mind is focused on "maximize the opponent's level of emergency", but you don't know how to do "start, here, here, here, here, finish", you are likely to play foolishly. A good rule is that when you play, focus on the highest level of abstraction you have mastered, and when you practice, focus on the next level up from there. So long as you practice regularly, this system will usually avoid plateaus. 

So there are a number of takeaways in the diagram above. 

  • Each level is one way to accomplish the thing in the level above it. So "start, here, here, here, here, finish" is just one way to strike flat with inertia toward the target. There are other ways and you may have to figure out another way when, for instance, you're on the run and in extremis. 
  • Each level generalizes across sports better than the level below it. So the body positions in "start, here, here, here, here, finish" might work for racquetball, but it might be an inferior swing for paddleball. In racquetball there's less time so the swing tends to be shorter. The ball is slower in paddleball, so a bigger swing may not only be desirable, but also necessary. Both sports favor a flat swing so "strike flat with inertia toward the target" is still a good pattern. But it doesn't extend to squash where underspin is desired on both the forehand and the backhand, in order to bring the ball quickly to the back court and then die before reaching the back wall. However, "sufficient pace within a margin of locational error" is an apt description of swing mechanics for racquetball, paddleball, and squash, as well as others, and you'll do well with "maximize opponent's level of emergency" in pretty much any racket sport.
  • Since our approach to racket sports attempts to favor no specific sport, our discussion will do its best to remain at the higher levels of abstraction. Say, the green and above in the chart, occasionally dipping into the yellow level for examples.

Predictive Versus Causal Models
In the sciences, we tend to have two different kinds of models:
  1. Predictive models tell us what to expect,
  2. Causal models tell us why to expect it.
Say we are trying to calculate the depth of water wells by dropping stones into the wells and measuring the time before we hear the "plunk" of the stone hitting the water. We could start with a dozen wells of known depth and drop some stones into them, then develop a regression model with a couple variables. And it might be a pretty good model, but it would do nothing to explain why we should believe the model. It's a purely predictive model. In contrast, we could start with a model of how a stone falls in a field of constant gravitational attraction and build a model that way. That is a causal model. It comes with an explanation of why we should believe it; why it works. The purely predictive model may actually give better predictions. After all, that's its job. And where the (simple) causal model doesn't take into account things like buoyancy and air resistance, the predictive model implicitly incorporates those things because of the way we built it; because those things were present in the data we used to build the model. But therein's the rub. We have few clues about how to improve the purely predictive model, whereas we can improve the causal model by analyzing it and seeing what causal contributors it incorporates and determining which causal contributors it doesn't incorporate and how to incorporate them. As an example from racket sports, you may develop a predictive model in your mind of how to work opponents by constantly hitting to the left. But that model may have been built from data you collected by playing right-handed opponents. Then the first time you face a left-handed opponent, all of the rules of your model that predict success break. Had your mind constructed a causal model it would have laid out rules to identify the opponents weaker side and then work to that weaker side because that will elicit weaker shots from the opponent. 

Going back to "start, here, here, here, here, finish", on its face, that's a predictive model. Your coach is saying, in essence, "swing like this and you will win, trust me." As we move up through the different abstractions of the game to higher and higher levels of play, our models of the game become more causal. Each level of abstraction offers some explanations of why we want to start "here", and why we want to pass through "here, here, here, and here", and why we want to finish "here". While the model becomes more abstract, the understanding becomes more concrete. Consider a topspin tennis swing (where the red and yellow abstraction levels will be different than those stated in the figure, because the figure assumes a flat swing). The predictive model says "swing up to the ball, contact it high on the strings, brush it with the strings, release low on the strings". That's kind of the "here, here, here, here" of a topspin tennis swing. Meanwhile, the causal model says "rolling the ball on the strings causes it to spin. The nap (fuzz) on the ball catches the air and gives the ball resistance to the air. As the ball moves toward its target, it essentially creates a wind around it. In the case of topspin, the top of the ball is spinning into the wind and the bottom is spinning away from the wind. So the force of resistance to the wind is greater on top than on the bottom. The greater force on top pushes the ball down faster than gravity alone would take it, allowing the striker to hit with greater pace and still keep the ball in the court." A big part of growth in your sport is moving from predictive models to causal models. Ultimately, coaches may teach the predictive models to beginners for simplicity. Predictive models are typically easier to understand. But the coaches need to (and usually do) understand the causal models of what they teach. When you start asking "why?" in your mind, your brain is trying to move from a predictive model of the game to a causal one. That's what it should do. In the rainbow chart above, you can think of each level of abstraction as being more causal. It answers the "why?" question raised by the level below.

A Model for Measuring Players

Our approach to racket sports--our abstraction--is a system for measuring players. It's a system that players can use to measure themselves, and also to measure potential opponents. In this section, we describe the system for measuring players. In later sections we will build on the system so that we can use it to improve players and exploit opponents. Our system is not entirely new. It's rooted in something Bill Tilden said in How to Play Better Tennis back in 1950:

Tennis matches are won or lost by the sum total of physical condition, courage, intelligence, experience, and stroke equipment of a player. If your sum total is greater than that of your opponent, you win; if it's less, you lose. 

This idea came to us in a more usable form through former tennis pro and now tennis teacher Dan Emmerson, and with some nuance from racquetball hall of famer Charlie Brumfield who says "It's not about ball striking, it's about everything else". Dan Emmerson's riff on this idea is to divide the player into five equal parts, measure each part on a scale of 1-20, and sum the total. While Dan attributes this to Tilden, we can't find anything more specific than what Tilden said in How to Play Better Tennis. So we give credit to Dan for this. And based on 70 years of progress since Tilden's book, we break down the five pieces a little bit differently than Tilden did:
  1. Athleticism: The player's fitness, speed, and other physical attributes. Mostly what Tilden called physical condition.
  2. Technique: Swing mechanics and associated elements.
  3. Game: Tactics, strategy, and fellow travelers. Similar to what Tilden called intelligence, with a bit of what he called experience.
  4. Competitiveness: The ability to sustain one's play and succeed in the face of various stressors.
  5. Confidence: The reliability of a player's judgement.

This model is an abstraction of the player. Each of these five contributors requires considerable discussion, and we will get to that momentarily, but given this taxonomy, a player can self-evaluate to get an estimate of overall player quality, giving each topic a total of 20 possible points. And similarly, a player can evaluate an opponent to get an understanding of the match up. All too often, we see players focus on one of these aspects at the expense of the others. More often than not, players will obsess on athleticism, or even one aspect of athleticism. They will work out in the gym, trying to build more muscle that helps them lift weights but does little to help them with a racket. But coaches can also be guilty of obsessing on one aspect. Typically, when a coach obsesses, it's on technique. We've seen lots of players who have reasonably good technique suffer because their coaches never get past the technique and onto the other 80% of play. So at first blush, our model for a player looks like this:

We'll discuss these contributors now, in the order in which they usually develop in a player.

Athleticism (0-20)
Athleticism is perhaps the most basic part of play, in that it's something that beginners bring to the game. They can develop athleticism as part of their progress, but they always bring something of athleticism into their play. We divide athleticism into nine components.

  1. Strength: The ability to do work with muscles.
  2. Size: The height, length, width, and sometimes the mass of a player.
  3. Speed: The ability to move fast over distance.
  4. Quickness: The ability to react to events in a very short time.
  5. Agility: The capability for rapid whole-body movement with change of velocity or direction in response to a stimulus.
  6. Coordination: The ability to orchestrate muscles in unison. This includes hand/eye coordination.
  7. Flexibility: The ability to move joints with minimal effort.
  8. Balance: The ability to hold unnatural positions with minimal effort.
  9. Stamina: The ability to perform continuous work without exhaustion; basically, cardio-vascular fitness.

Different racket sports may favor one or another of these athletic components, but all of these contribute to every racket sport. For instance, table tennis favors quickness. The ball is moving at 100 MPH over a 9 foot table. That gives a total time of less than one-tenth of a second to react and take your shot. Quickness is essential. Squash, by contrast, favors stamina. Rallies are brutal and long. Professional squash tournaments often instrument players with heart rate monitors, and much like tennis tournaments display service speed for spectators, squash tournaments display heart rates. SquashMad.com reports that In a match between Ramy Ashour and Tarek Momen, both players regularly peaked between 191 and 199 BPM during the match, and the average heart rate throughout the monitored time was 171. This would be time to call 911 for any normal person but for top squash players it's all in a day's work.

Although basketball Coach John Wooden famously quipped that "you can't train height", most of the rest of this--including size--can be trained. If you score yourself low on athleticism, you may be able to improve as a player by identifying which of these nine areas are weak, and working on those. To reiterated, one pattern you'll see in this discussion is to work on the weak stuff. If you're strong as a bull but can't touch your toes, maybe take a break from the weight room and spend some time in the yoga studio.

These criteria create an interesting fabric for comparing the athletic requirements for different racket sports. We've assigned seven racket sports requirement levels between 0 and 10 for each of the nine factors. The scores are based on our experience with the sports, and we think the scores are fair.

When we show this data as a radar or "spiderweb" chart, some interesting things pop out. 

  • While the athletic requirements for tennis are a bit more than for the other racket sports, the difference is contained mostly in the "size" component. What's up with that? The tennis serve is arguably the most difficult movement in all of racket sports, largely because it requires tremendous spin to be put on the ball in order to achieve any power...for most of us. Geometry just doesn't afford the opportunity to hit a flat ball with pace that both clears the net and stays in the service box. If we want to rely on gravity to keep the ball in the service box, that requires slowing the serve down. But if you can strike the ball at a height of 10 feet, the geometry changes. you can hit a flat serve that clears the net and does not rely on spin to bring it down in the service box. This is why the current great servers, like Ivo Karlović (6'11"), John Isner (6'10"), Milos Raonic (6'5"), and Nick Kyrgios (6'4"), are all taller than 6'3", which is about the height one needs to be in order to strike the ball at 10 feet. To be sure, the great servers still put good spin on the ball. And shorter players like Roger Federer, who is only 6'1", have developed monumental serves. But height is a decided advantage on a tennis serve, and the taller a player is, the more margin for error they have, due to the basic geometry of the game. Too much height may foreshorten a player's career through injuries and joint problems, but gives a big edge, on-court.
  • Squash comes out high in athletic requirements, but the difference is in stamina. Squash can be a grueling slog with 60 shot rallies being common. Lots of people die on the squash court. An October 2008 story in Vanity Fair proclaimed squash "The Most Dangerous Game", and a number of academic studies have been done to understand why there are so many sudden deaths on the squash court. Squash is a very good sport for your health, so long as you don't die playing it.
  • Table tennis comes out low in athletic requirements, but this is largely due to the absence of a serious strength requirement. The racket is feather-light, at about 90 grams, and table tennis strongly favors flexibility, quickness and agility over strength. The flexibility requirement may not be clear...until you try to retrieve a ball that drops below the level of the table. Then the flexibility requirement is obvious. And while size is a factor in table tennis, it is opposite of most racket sports: table tennis favors smaller players. It's harder to hit to the body of a smaller player. All of this explains why ten and twelve year olds can compete favorably in table tennis at the regional level. Tomokazu Harimoto, the Japanese ping pong prodigy, started playing ping pong when he was just 2, and was reaching the finals of major world level tournaments at 14 years old and about 130 pounds. No normal human could have any hope of swinging a tennis racket at two years old (note that Harimoto had to hit to stand on a platform to play at that age in order to reach the table). A useful observation from this is that kids interested in racket sports at a very young age might start in table tennis years before they are ready to start in other racket sports. Developing the agility and muscle memory at a very young age may be a superb preparation for "heavier" racket sports later on, as well as giving them a game they can play throughout their lives, rain or shine.
  • The chart also shows that table tennis has lower stamina requirements. We have two strong pieces of evidence to support that claim. Firstly, our own work with heart rate monitors indicates that table tennis seldom brings a player into what are traditionally called the "exercise zones". Typical heart rate levels are just below the exercise zones. The rapid-fire adjustments to the ball make it feel like you exert more energy than you actually do. If you can't get the ball in one step, it will be past you anyway. This leads to a different kind of workout. The other piece of evidence is in tournament structures. A typical table tennis tournament starts with a full round robin, and the results of the round robin are used for seeding in an elimination tournament. That's a lot more match time than other sports.

Technique (0-20)  
Technique is the physical tool set that you use to play. It typically develops after athleticism, but usually before a player develops a game. Technique includes:

  1. Swing Mechanics: The ability to strike a ball (or a shuttlecock) effectively.
  2. Racket Preparation: The ability to maintain the racket in position to strike.
  3. Eye Control: The ability to focus on fast moving or subtle things.
  4. Footwork: The ability to move fluidly and efficiently.
The specifics of all of these things vary by sport. For instance, a table tennis player may have great eye control on a small table and follow the ping pong ball skillfully, but have serious problems tracking a tennis ball across the 78 feet of the court from baseline to baseline. But conceptually it's the same thing. The difference, in this example, is most likely in the eye muscles which, like other muscles, tend to optimize themselves to the specific tasks they are forced to perform. A table tennis player with good eye control will tend to develop good eye control in tennis with continued play because the eyes adapt to the new task they are forced to perform. 

Game (0-20)
A player's game usually develops after he or she develops playing technique. They know their swing mechanics and their shots, and now they use those shots to produce points in rallies. A player's game includes:

  1. Tactics: A system for responding to situations on the court.
  2. Strategy: An overall approach aimed toward prevailing in the competition.

Tactics and strategy are sometimes confused. To help understand the differences, tactics are what a Lieutenant uses in battle, and strategy is what a Field Marshal uses to win a war. Charlie Brumfield is one of the best racquetball and paddleball players ever to step onto the court, and his game skill has allowed him to play at an extremely high level into his 70s. In a rally, Charlie has a tactical system that tells him what to do in each situation. When he moves into coverage, he anticipates two possibilities: the opponent's most likely shot, and the opposite shot. Charlie expects the most likely and prepares for the opposite. This makes it exceedingly difficult for the opponent to choose a winning shot. That's tactics. That's the Lieutenant. But Charlie is also a Field Marshal. His tactical plan services the strategic plan, which is to divide and conquer: to identify the part of the court that the opponent can defend as well as the part that the opponent cannot defend, and to grow the part that the opponent cannot defend with each successive shot in the rally until he can safely put the ball into that part of the court. That's strategy. That's the overall plan to prevail in the match. Both tactics and strategy can be learned on-court and off-court, but tactics probably favors on-court training whereas strategy probably favors training in the clubhouse. 

Competitiveness (0-20)
Some people are naturally competitive. Others aren't. There are players who have a great game, but can't pull out the big wins. Some players regularly make it to the semifinals and then wither. We suspect that a big part of that is that they have never trained for competitiveness. It can be trained, and it doesn't require Vince Lombardi's "winning isn't everything, it's the only thing" attitude. Competitiveness is two main things:

  1. Enduring Stress: Sustaining your ability to play in the face of stressors.
  2. Exploiting Stress: Placing stresses on the opponent to impair his or her ability to play.

Stressors can take many forms: injuries, weather, court surfaces, heckling, fear of an opponent, fear of critical situations, fear of crowds, fear of the referee, etc. Likewise, stressors can be exploited by a player to impair an opponent. Terry Gross did a famous interview of Andre Agassi in 2009. It's one of the best sports interviews ever conducted and deserves a listen by any serious racket sports player. Amongst other things, they discussed Agassi's last real professional match at the 2006 US Open against Marcos Baghdatis in the second round. Terry reminds Agassi that he was fortunate that Baghdatis sustained an injury in the fifth set. But then Agassi asserts that he "earned" that injury. That he and Baghdatis both played the most brutal form of tennis, one designed to take everything out of the opponent until they have no will to continue. That is just one way to exploit stress on an opponent. And in that particular match, Baghdatis did much the same, moving Agassi left to right through long rallies that aggravated Agassi's existing back problems. After that match (which Agassi eventually won after more than four hours of play), both players required stretchers. An opponent can be stressed indirectly by "working" a referee. An opponent can be stressed by delays or by trash talk. There are lots of ways that one player can put a thumb on their side of the scale. But there are also lots of other ways that a player can put stresses on themselves: a "bad call" from an umpire or referee; a missed shot, especially a shot that just barely misses; an opponent's shot that shouldn't have worked but did, like one of those tennis shots that was supposed to be a deep drive but hit the tape and barely rolled over the net; an "act of nature", like a gust of wind that blows the ball; equipment failure; etc. In The Inner Game, Gallwey talks about a match he played against Jimmy Connors where he won the match, but Connors didn't concede. He even walked off, and somehow that caused the umpire to reverse the call, and when play continued, Gallwey fell apart and Connors went on to win the match. The ugly truth of racket sports is that there is a whole lot more that can go wrong than can go right. Anything that goes wrong can cause stress. And so a competitive player learns how to cope with stress. It's 20% of the equation.

Confidence (0-20)
Before Super Bowl I, Fred Williamson of the Kansas City Chiefs (nicknamed "The Hammer") captured national headlines by saying that he would knock the Green Bay Packers' starting receivers, Carroll Dale and Boyd Dowler, out of the game. "Two hammers to Dowler, one to Dale should be enough," he boasted. That's not confidence, at least not as we mean it. That's cockiness. And "The Hammer" got hammered, by one of the Packers in the fourth quarter and he himself was knocked out of the game. Confidence as we mean it here has nothing of that. It's more akin to what statisticians call a "level of confidence". It's about the reliability of one's judgement. And a player's judgement lives on long after the player is gone, which is why we still read Bill Tilden 65 years after his death. Confidence has two basic components:

  1. Self-Esteem: An understanding of what you can do (in the context of your opponent's play).
  2. Humility: An understanding of your limitations (in the context of your opponent's play).

For instance, "I am confident that I can make this crucial serve effectively into my opponent's backhand because my pace is sufficient, and I am also confident that I cannot make this crucial serve effectively into my opponent's forehand because my deception is not good enough and my opponent is too quick". Confidence grows naturally with experience, but there are also ways to train confidence. Visualization, is one example. When you make a mistake, you visualize in your mind what you should have done instead, and erase the mistake from your mind.

We now have a more complete model of the player.

The criteria are now fine enough, and concrete enough, that a player should be able to self-evaluate him or herself and also to evaluate an opponent. The big questions are how to train to improve one's score as a player, and how to use your evaluation of your opponent to gain an advantage. 

Now that we know where we stand as a player, the goal is improvement. One straight forward observation is that if you already score 20 for an aspect, no improvement is possible, so it's a fool's errand to focus your training there. You've already topped out. And if you currently score a 19, there's very little room for improvement, so there are few ways to improve and improvement will be difficult. If you currently score 18, there is a little more room for improvement, so it's easier than if you score 19, but it's still very difficult. Moreover, on average, the better you are at an aspect, the harder it is to improve. We've drawn a notional chart to indicate the level of effort required to increase your score when starting at a given level.

The obvious conclusion from this chart is that to train efficiently, you want to work to improve the areas where you are weakest because the effort is lower for a given level of improvement. If you score a 5 on fitness and a 15 on confidence, it's a whole lot easier to bump the fitness up to 6 than it is to bump the confidence up to 16. Unfortunately, lots of players train their strengths. They've had success there in the past, which is how they got strong in that area, and so they go back to the hole. Then they reach plateaus that they can't get out of. Likewise, we have seen coaches who don't want to move on to game aspects until the player's technique is a perfect 20 because they are really good at training a player's technique. Again, they go to the place where they've had success. But getting to the perfect 20 is almost impossible. And so the player languishes in intermediate levels with a very nice swing while easy improvement is available in other aspects of the player. The player becomes frustrated losing to players with far weaker technique, and doesn't understand why, because they haven't learned that game, competitiveness, and confidence need to be included in the evaluation of their opponent. Their model of a player is deficient. And because it's a predictive model rather than a causal one (e.g. "get your swing mechanics right and you'll win, trust me") they don't have the perspective to improve the model. They don't know why their training isn't working. Eventually, they leave the sport disappointed.

All five aspects of a player: athleticism, technique, game, competitiveness, and confidence can be trained and improved. In fact, there is at least some element of each that can be trained on-court, and some element of each that can be trained off-court. Off-court training is particularly useful to those of us who don't live at the club. Off-court training allows us to make improvements while at home or work. On-court training is usually more fun. Not always, but usually. Some on-court drills are brutal.

We will examine two different approaches to improvement. The two approaches can, and should be used together.

  1. Focused Training: Isolate an aspect and focus on improving it.
  2. Cross-Training: Identify the stronger aspects and use those as tools to improve the weaker aspects.

Focused training is good, and we will deal with that first, but cross-training is the most important way you can train, and we will cover that momentarily.

Focused Training
In focused training, we isolate an aspect of play and work diligently to improve it. Usually, this means looking deeper into that aspect to find the specific component where the weakness is, and training that. 

Let's say your self-evaluation score on athleticism is low. But "athleticism" is too broad to train for improvement. Training to be more athletic is like studying to be smarter. The categories are too broad and without refinement, failure is likely. So you identify which parts of your athleticism are wanting: strength, size, speed, quickness, direction change, coordination, flexibility, balance, or stamina. Each of these is specific enough to improve. For each part of each aspect, we give some general ideas for improvement. These are not exhaustive, but provide a reasonable outline for a training course to improvement, and given these examples, it's usually possible to find other means of focused training to improve that aspect.
  • Strength: Strength training can be done on-court or off-court. On-court, you can wear a weight vest, preferably a light one. You also might weight the racket or wear ankle or wrist weights, but we recommend against that as this can lead to injury, but some players have had success that way. However, off-court, any of these will work. You can wear a (possibly heavier) weight vest at work and train your strength throughout the day. Wear ankle or wrist weights on your evening stroll. Even one pound "knuckle weights" will make your walk more challenging. You can workout in the weight room if that suits you. And if you want to reach your maximum potential of athleticism, you'll have to. However, you should be aware that few weightlifters or bodybuilders end up as good racket sports players. They tend to build bulk that gets in the way of their own movement. The body's muscles are largely divided into fast twitch and slow twitch muscles. The slow twitch muscle groups tend to be larger, and so these are the ones "physique athletes" usually try to build. Racket sports rely much more on the smaller fast twitch muscles. Big muscles often just get in the way, and so racket sports athletes tend to do best in the weight room when they introduce "balance challenges" into the exercise. Here, for example, is a photo of Chinese table tennis team player Liu Guiliang doing dumbbell raises while standing on physio-balloons to challenge his balance in the lift. The balance challenge makes the exercise more difficult. As a consequence, he can use smaller weights which reduces the risk of injury. In addition, the balance challenge engages the fast twitch muscles from the balls of his feet up to his wrists. This kind of strength training is one of the tools that got Liu Guiliang into the world's top 4 in his sport.

Bosu Balls are also excellent for engaging the fast twitch muscles, and can be substituted for the balance balloons Liu is using in the photo. The Bosu Ball is like half of a physioball. It can be turned so that either the flat side or the round side is down. Round side down tends to be more challenging. For most racket sports strength training, round side up works fine, but if you want the extra challenge, turn the round side down and balance on the flat side. Some athletes actually use a physio ball (full-round ball) in this way. For instance, they step on the physio ball with a weight bar and do curls or even squats. This is quite dangerous, and we don't recommend it, even if you see others in the gym trying it out. There are lots of ways to use a physio ball as a balance challenge for weightlifting: sitting on it is okay. Standing on it is not smart. 

Bicycles are also a useful way to build strength. You can ride hills, or, if you are stuck with a stationary bike, crank it up to a high level and do interval training on it. Some gyms have stationary bikes that are specially cranked down to make them more resistant for strength training. Ride for two to three minutes on a setting that causes your quads to burn, rest for a few minutes, and ride for another couple of minutes. 

To train specifically for wrist strength, gyro balls like the PowerBall are really good. 

We actually prefer the gyro balls with the handle, but those don't seem to be available anymore. With the gyro ball, you start the inner ball to spin and then use your wrist to keep the ball spinning. you can get these up to a pretty good speed (thousands of RPMs). You may have heard tennis or table tennis players talk about a "heavy ball" as one with a lot of spin. As you spin the gyro ball faster and faster you will know what they mean. At rest, the gyro ball probably weights about 8 oz. But as you spin it up faster and faster, it will feel like it weighs five pounds or more. And you will get a serious forearm workout by keeping the ball spinning. But don't overwork the gyro ball. Too much gyro can aggravate tennis elbow. The more expensive PowerBall models have built-in sensors that will give you the gyro ball's RPMs. That's a nice feature, but you pay a lot for the sensor.

To be sure, the functional training community of sports physiologists has a lot to say about strength training for sports. We highly recommend Functional Training for Athletes at All Levels by james C. Radcliffe who is the head strength and conditioning coach at the University of Oregon. Radcliffe has trained many of the athletes in the University of Oregon's exceptional NCAA and intercollegiate sports programs, as well as authoring a number of scholarly papers on sports physiology. We note that the book focuses on the athletic requirements of the big NCAA team sports like football and basketball, but most of what he says can be applied to racket sports as well. Radcliffe gives more than 100 exercises tailored to the different aspects of (functional) training. Most of Radcliffe's exercises don't require any sundries like a weight bar. He also discusses warmup and gives a good discussion of dynamic warmup. 
  • Size: In general, size in court sports is a bad thing. To be sure, tennis players taller than 6'3", like John Isner, have some advantage in that they can hit a flat serve that doesn't require gravity to pull it down. But taller players also have an array of injury problems. The more important issue of size is weight, and most amateur players are heavier than ideal. One way to reduce the weight is to play more, particularly in racket sports like squash or paddleball that burn a lot of calories and increase metabolism. We recently had the pleasure of watching a slightly plump former racquetball pro try his hand at squash. After he finished his match and slid his body down the outside of the glass and into a lump on the floor he looked around the squash club and noted: "There. Are. No. Fat. People. Here!" This is actually a pretty good yardstick to determine whether trying to train in a different sport will help. If all of the people at the club where they play that sport are lean and wiry, and you're trying to lose some weight, maybe try a game. 
But just as diet can't compensate for lack of exercise, exercise does not make up for bad diet. There are obviously a world of weight loss diet plans out there, but racquetball hall of famer Shannon Wright is a strong proponent of Dr. Joel Fuhrman's Eat to Live diet. Shannon is also a PhD/MD and knows her way around the human physiology, especially racket player human physiology. So Eat to Live might be a good place to start. Dr. Fuhrman's plan is based on nutrient-dense foods, mostly dark-colored vegetables and fruits, and whole grains. Fuhrman rates foods with an Aggregate Nutrient Density Index (ANDI value), where kale has the highest rating at 1000 and Coca-Cola has the lowest at 1. He allows junk foods and other low-ANDI value foods in his diet, but recommends that they be limited in the same ways that one would limit recreational drugs. Dr. Fuhrman gives a page of ANDI values for common foods on his web site, and these might be good to look at even if you're already at a good weight. Dr. Furhman acknowledges that strict adherence to his diet provides insufficient calories for athletes, but it can be adjusted to the activity level of your life. Again, there are lots of other diets as well. Eat to Live is only a starting place.
  • Speed: Speed can be trained. We are not fond of wind sprints--especially for older players--due to their impact on the knees. We'd like to save as much of our knee impact budget as possible for the court. But one of the best ways to improve speed is with a bicycle. If you've got a bike that has a rack and pannier bags, use it when you need to get a few things at the store. Use it to go to the library. If work is within range, ride to work. Same for the gym. Bike to your workout and you get a warmup in without costing you any time. Jump ropes, particularly speed ropes are another great way to train speed. Buddy Lee trains Olympic athletes at the Olympic Training Center. He was an Olympic wrestler himself and has developed some impressive routines. Most of these are not specific to a particular sport. He also has created some great speed ropes. He has a lot of information on his web site, where he also sells his speed ropes. They are also available on Amazon.com. Here's a video Buddy uses to introduce the rope to potential trainees. It's quite impressive and deserves a view.

But there are some important caveats about jumping rope. If done correctly, on the correct surface, jumping rope is low impact. Please do not jump rope on concrete or a hard court. At least not for more than a minute or two. We see jump ropes in cardio-tennis sessions on the hard court. Be very careful. If you play squash, badminton, or indoor racquetball on the other hand, a well-sprung hardwood floor like those of high quality indoor courts is ideal for jumping rope. Plyometric training is another way to improve speed. Plyometrics typically involve an aerobic step or similar step. You can do slalom lunges across the step, or similar exercises. The benefit is similar to the jump rope. We find it more boring than a jump rope but if it works for you it's probably good. Similar caveats as with the jump rope. Do your work on a surface with some give. Also, a lot of plyometric routines are based on box jumps. Box jumps are great, but you have to be very careful. If you are a bit too ambitious, you can cause yourself fairly severe injuries. 
  • Quickness: The best way we've found to train quickness is to play table tennis. If your main racket sport is something else, training with table tennis will really work on your quickness. Jumping a speed rope will also train quickness, but as before, try not to jump rope on concrete or other similarly hard surfaces. You can also drill, on-court, to train quickness. If you are a racquetball or paddleball player, you can stand about five feet from the front wall and do continuous reaction volleys with yourself. This will feel somewhat like a boxing workout on a speedbag, and your quickness will improve within a few workouts. If you play tennis, you can set the ball machine near the service line and assume a position at the net and practice volleys. Pretty much anything on a badminton court will enhance your quickness. And while the fast twitch muscles are the foot soldiers of quickness, the eyes and ears are the forward deployed commandos. Regardless of how you train, to become quicker, you need to learn to see and hear the play. You need to learn to identify and monitor the cues. In enclosed court sports like racquetball, one training method is to go onto a dark court and do your drills. You have to work harder to see the ball, and as a consequence, you place more emphasis on hearing the ball off the racket and the wall. But you can also train your eyes and ears by simply being more deliberate. On your evening walk, look and listen carefully. Try to pinpoint the bird you hear, and try to see any changes from your last walk. Similar exercises work on-court. Some coaches teach that your on-court warmup is not for your muscles (those should have been warmed up already, maybe on an elliptical trainer or stationary bike), but for your eyes. Start short and slow. Watch the ball carefully, and then gradually move back, hitting longer and finally faster balls, maintaining the same focus you had for the short, slow balls. 
  • Agility: Experts are still trying to come to agreement on what exactly agility is. And without a definition of the thing, it's really hard to put together a training program. Jeremy Sheppard and Warren Young proposed a good working definition  in a 2006 paper in the Journal of Sports Sciences, a scholarly journal for sports physiologists. They say that agility is "a rapid whole-body movement with change of velocity or direction in response to a stimulus”. The change-of-direction part is key not just to agility, but to athleticism as a whole. In his interview with Terry Gross, Andre Agassi confided that one of the smartest things anyone ever told him about tennis was when he first met Gil Reyes (his trainer for much of his career), and Gil told him that tennis doesn't require you to run great distances, it requires you to run five steps, change direction, and run five steps the other way. And Agassi's realization of the importance of direction change completely altered the way he trained. Gil Reyes' main point--that changing directions is key to athleticism and player performance--also holds for other racket sports. And the fact that it took Gil Reyes for the hard-training Agassi to realize this suggests that elastic potential is often overlooked by players and coaches as a significant component of their athleticism. But let's examine the impact on your game. Say that the ball is moving at 60 MPH. That's probably a good round number for most racket sports. If you can improve the time it takes you to change directions by just 1/20 of a second, that makes a difference of about 5 feet. That's a full step on the fly. How many balls do you miss getting to by less than a full step on the fly, and how would it improve your play if you could reach all of those? Skier drills on the jump rope are a good tool to train for pivoting and changing direction (see the Buddy Lee video above for an example). But slide boards may be the best tool available to most players to train for this. However, many gyms don't have slide boards and so they can be dismissed by their absence. They are also not very expensive and most players can afford one of their own or convince their club that it's worth the investment. Most slide boards roll up for storage in small places. 
    Here's a good video of speed skater Kevin Jagger training on a slide board. The video is in two parts, part one showing Kevin in his first days with the slide board and part two showing Kevin working the slide board a year later. The takeaway from the video is that on the bounce, where Kevin's foot pushes off the chock at the end of the slide board, he's cut the bounce time in half with that year of slide board workout. He goes from about two seconds to about one second on each bounce. So he's gained a second. In one second, a ball moving at 60 MPH travels more than the length of a whole tennis court. Of course the slide board isolates this kind of activity. Working on the slide board would be like playing tennis on glare ice while wearing brand new leather soled shoes. We don't do that. The actual gain is less than that full second, but it is still substantial. 

  • They go on to note that "Agility has relationships with trainable physical qualities such as strength, power and technique, as well as cognitive components such as visual-scanning techniques, visual-scanning speed and anticipation." This means that your off-court agility training can include training your eyes or watching video of play to develop better anticipation.   
Elastic potential is an umbrella for springiness, bounciness, and the ability to quickly pivot and change directions. In his autobiography Open, Andre Agassi confided that one of the smartest things anyone ever told him about tennis was when he first met Gil Reyes (his trainer), and Gil told him that tennis doesn't require you to run great distances, it requires you to run five steps, change direction, and run five steps the other way. This kind of direction change is part of elastic potential. And the realization that elastic potential really mattered completely changed the way that Agassi trained. Gil Reyes' main point--that changing directions is key to athleticism and player performance--also holds for other racket sports. And the fact that it took Gil Reyes for the hard-training Agassi to realize this suggests that elastic potential is often overlooked by players and coaches as a significant component of their athleticism. But let's examine the impact on your game. Say that the ball is moving at 60 MPH. That's probably a good round number for most racket sports. If you can improve the time it takes you to change directions by just 1/20 of a second, that makes a difference of about 5 feet. That's a full step on the fly. How many balls do you miss getting to by less than a full step on the fly, and how would it improve your play if you could reach all of those? Skier drills on the jump rope are a good tool to train for pivoting and changing direction (see the Buddy Lee video above for an example). But slide boards may be the best tool available to most players to train for this. However, many gyms don't have slide boards and so they can be dismissed by their absence. They are also not very expensive and most players can afford one of their own or convince their club that it's worth the investment. Most slide boards roll up for storage in small places. 
Here's a good video of speed skater Kevin Jagger training on a slide board. The video is in two parts, part one showing Kevin in his first days with the slide board and part two showing Kevin working the slide board a year later. The takeaway from the video is that on the bounce, where Kevin's foot pushes off the chock at the end of the slide board, he's cut the bounce time in half with that year of slide board workout. He goes from about two seconds to about one second on each bounce. So he's gained a second. In one second, a ball moving at 60 MPH travels more than the length of a whole tennis court. Of course the slide board isolates this kind of activity. Working on the slide board would be like playing tennis on glare ice while wearing brand new leather soled shoes. We don't do that. The actual gain is less than that full second, but it is still substantial. 

We've mentioned that bouncing or "springiness" is a big part of elastic potential. You can see that springiness in Kevin Jagger's video. And the slide boards and jump ropes are really training springiness more than anything else. Here's a good experiment that's changed the way a lot of racket athletes train and play. In fact, it's changed the way lots of athletes in other sports train and play as well: Hold your hand out over a desk or table. Keeping your arm firm and just using your open hand, hit the table as hard as you can. Listen to the sound. Now, holding your hand out over the table as before, use your opposite hand to pull the fingers of the suspended hand up, like pulling back a spring or pulling a bowstring. Now release the bowstring and let the open hand that was sprung back hit the table. Listen to that sound. If you're like most people, that sound was much more powerful than the first. That's the difference elastic potential and strength. Elastic potential is explosive power. As another illustrative example, consider an offensive lineman in football. When the ball snaps and they start to block the opposing defensive lineman, they lunge into action. That's their elastic potential. After that, they push the defensive lineman back with strength. But that first explosive lunge is much more powerful than the rest of the block. But it's also much more important. In that situation, the offensive lineman (and the defensive lineman too for that matter) elastic potential is far more important than raw strength. This is one of the big "lightbulb moments" in what's known as "functional training", which is training for athleticism rather than training for physique. Most athletes train more for elastic potential.

Slide boards were designed to train speed skaters. But they've been a secret training ingredient of some of the most successful racket sports players (we were introduced to them by Chris Crowther, former top 4 racquetball player). Basically, you put some silk booties over your shoes and slide back and forth on the slippery slide board surface. There are chocks at each end so that you don't slide off, and when you hit the chock, you change directions and go the other way. The caveats for slide boards are a different than for jump rope. Slide boards are very low impact since you are constantly sliding. And you need a smooth hard surface to slide on. So concrete is a very good surface for the slide board.     

Because of the nature of speed skating, where the change in direction generates the thrust, skaters have to kick off from side-to-side and they use a lot quadriceps and calf muscles. We have better traction in racket sports. So we can get more of a spring from our shin muscles. In fact, these (principally the tibialis anterior that runs vertically just to the outside of the shinbone), are key to a racket athlete's bounce. The reason goes back to the goal of reducing the amount of time needed for the direction change. It takes time to coil up and uncoil the kinetic spring. It takes time to bend the knee, and it takes time to unbend it. And if the bend continues to the waist, more time. The more you can control the bounce with the spring of your ankle, near to the point of contact with the ground, the less time spent to coil and uncoil; the less time it takes to change direction. We still need the quads and the glutes that the slide board trains, but we need the shin muscles just as much or maybe more. These are the main bounce muscles. Some plyometric exercises are very good for these bounce muscles. Low box jumps are probably the best example. These can be done with an aerobic step. Typical aerobic steps come with some blocks that can be installed at either end, and this allows the height of the step to be varied. Use those to raise your bed or something. You won't need them here. The kind of jumps we want to do are just fine with the lowest step (no blocks on either side), because we are not interested in the whole jump, just the bounce; just the shin. In fact, a plain old board will do if you don't have an aerobic step. To do these jumps, stand in front of the step and using your shin muscles, bounce up onto the step and then bounce back down without touching your heels to the ground. Repeat. You are not bending your knees in this exercise. You don't want to lock them out, but you don't want to bend them either. It's not about the big muscles of the thighs. It's about training the shin muscles to bounce. When you pivot and turn on the court, you want those bounce muscles to take the bulk of the load. But be careful with the aerobic step. Don't try to do too much or injuries become more likely.
  • Coordination: There are a couple of tools we like to train coordination. One is the speed rope. Same caveats as before, don't jump on concrete, and work to do some of the more advanced jump rope exercises like skiers and twisters which emphasize coordination. Coordination will come quickly because you need to engage upper body, lower body, and mid-body all at the same time. We also like the agility ladder for coordination. The agility ladder is a bit boring until you try some of the more advanced patterns and exercises (as shown below), but once you get used to those, you will probably come to like the rhythm. But always remember to engage your arms when running on the agility ladder. Your arms should swing in a rhythm opposite of your feet. When your left knee is up, your right elbow is up. Forcing both the elbow and the knee to rise and fall at the same time is good for coordination. However, like with the jump rope, avoid using an agility ladder on concrete.


A grass surface is ideal for the agility ladder. An artificial turf surface, or a well-designed running track, is good. A well-sprung hardwood floor is better. Once again, we see cardio-tennis clinics and workshops lay an agility ladder out on a hard court surface, and that is unfortunate because it can cause joint problems. 
  • Flexibility: Yoga is the gold standard for training flexibility. But yoga is a big commitment. It really takes several hours a week for several months to get satisfactory improvement in flexibility. That's in part because we tend to train our muscles to be big in girth, but not long. Yoga trains the muscles to be long. And just as it takes a while for a body building routine to make your muscles bigger around, it takes a while to make your muscles longer. Athletic stretching, especially immediately before (and immediately after) play has somewhat lesser rewards, but the rewards are immediate. To be sure, you should stretch before and after play anyway. It reduces injuries and prepares the muscles and joints for activity. It can be combined with yoga or other flexibility exercises as well. There are different schools of thought on pre-match stretching. Some experts advise dynamic stretching only, and static stretching after the match. The claim is that static stretching, like reaching down and touching your toes, relaxes the muscles and reduces their reactive snap in play. Other experts recommend static stretching before and after play. In our opinion, if you are prone to joint injury, static stretching before play should be mandatory. There is also a different kind of athletic stretching that we've become fond of. It's assisted athletic stretching. Many personal trainers have learned how to stretch their clients. The trainer will use his or her weight and strength to stretch the client. This is good, and if you have a personal trainer you should talk to him or her about it, especially if you have flexibility issues. The luxury option is a specialize stretch therapist. StretchU is probably the most important practitioner of this approach. StretchU is basically like another gym membership, and a fairly expensive one at about $100/month, for which you can get 4 stretches per month. But their physical therapists are highly trained, and if you have serious flexibility issues, it might be worthwhile. By comparison to a typical stretch session with a personal trainer, a StretchU session will be less painful and more taylored to your specific injury or concern, and you will feel more flexibility when you are done. It's like a massage session, except instead of massaging the muscles, they stretch them. 
  • Balance: Yoga is an excellent way to train balance. And yoga delivers results in balance before it returns results in flexibility, largely because you don't need to grow muscles longer to improve balance where you do need longer muscles for flexibility. It's more about muscle memory and learning to activate the fast twitch muscles. But if you can't do yoga, the Bosu Ball is a great tool for training balance, and it's pretty simple. One of the things it does is to get you in touch with your fast twitch muscles right away. If you stand on one foot on the Bosu Ball, after maybe 30 seconds (or maybe 10), your leg will start to shake, and the shaking will increase. That's the fast twitch muscles firing in an effort to keep you in balance on the ball. If you step on the Bosu Ball a couple days later, it won't be as bad because those fast twitch muscles have already built up a memory of what to do. You can also squat on the Bosu Ball.

Some athletes squat with dumbbells on the Bosu Ball, others simply reach their hands out in front of themselves when they squat down, as in the picture above. If you hold the squat in the lower position, you will feel the fast twitch muscles firing in just a few seconds.
  • Stamina: Running was traditionally the way athletes trained for stamina. For many years, Andre Agassi ran five miles every morning. However, he came to reject that kind of running in his routine. We tend to shy away from traditional distance running to train for stamina because it can be very hard on the knees. Many good endurance athletes have had to have their knees replaced due to the joint damage caused by the constant pounding incurred by running. Bicycles are easier on the body. And hill riding is very serious stamina training. If you can't get on the road, the elliptical or rowing machine at the gym is a reasonable substitute. We particularly like an elliptical trainer called the Long Stride trainer. It allows you to change the length of your stride while exercising. All of these machines emphasize lower body endurance. The muscles in the lower body tend to be the largest muscles. Engaging them triggers greater blood flow and greater movement of oxygen as opposed to engaging only smaller muscles. For similar reasons, the jump rope is also excellent for training endurance. This is one of the reasons boxers depend so much on the jump rope in their training. There are also on-court drills. For most sports there are so called "star drills" where you set out cones in a diamond shape on the court and mark a position in the middle of the diamond. You run to the first cone and return back to the middle, then the second and return, third and return, fourth and return, then repeat. All of this said, many racket sports players will find all of these forms of stamina training too boring. A more interesting approach to training stamina is to go play some squash. Of course, squash players themselves do a great deal of difficult work to build stamina, but the sport requires so much of it that if you are coming from another racket sport, playing a little squash will greatly increase your stamina, and you will see the results very quickly. Badminton may also do the trick. 

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This is probably the most fruitful way to train. With your honest self-evaluation in hand, you know which aspects you are strongest in, and which you are weakest. But importantly, each aspect touches on all of the other aspects. The diagram below shows a small sampling of how the different aspects connect.

So the key to cross-training is to use your strong aspects to up-level your weaker aspects. Say, for example, that you evaluate high in athleticism and low in technique. Ketthong Pisa, Assistant Coach at the San Diego Table Tennis Association, has a powerful way of training through that imbalance. Ketthong is also a Kung Fu blackbelt. His approach, which we call "Kung Fu Racket" uses his strength not so much to move the racket around, but to prevent the racket from going where you don't want it to go. In Kung Fu, you often must take a blow. The opponent's purpose in delivering the blow is to make your body move into a position you don't want it to move to. Your Kung Fu mastery uses your strength and athleticism to absorb the blow without letting the blow move you from your preferred place. 

Let's go back to our earlier example, where your coach tells you to start your swing "here", then move through the positions "here, here, here, and here", finishing in the position "here". The Kung Fu Racket method uses your strength not so much to move the racket through those positions, but to prevent your body from taking any other positions. In essence, you use your muscles to create a channel in which the only motion possible is along the desired path. And then it is simply a matter of letting your body flow. This indeed requires a lot of strength because the forces on the court--time, motion, the ball, opponent-induced distress--are all trying to pull you away from that preferred swing path, much like an opponent in a Kung Fu fight tries to move you from your preferred path with a blow. We've found that the Kung Fu Racket approach works. So long as you have the strength to start with, it leads to improved technique that reduces any imbalance between athleticism and technique. 

This is just a small part of one example. Associated with each line in the diagram above are training paths going in each direction. So, just as Kung Fu Racket is a way to use strong athleticism to improve weak technique, there are ways to use strong technique to improve weak athleticism. 

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