Thursday, April 28, 2005

Vision

Brian Nolasco relays some of what he learned at the recent Nike Championship Basketball Clinic in Milwaukee. Below is some of what Brian says about Princeton Coach Joe Scott's presentation:
Also, he talked about players who hold the ball. When this happen, it could mean two things. Either, they are selfish, or they are blind. Selfishness is very easy to correct. Blindness is a bit tougher. But, you can teach them to get better and make them efficient. Perhaps they won't be creative, but they will know what to do next.
I often experienced the held ball in hockey. Of course in hockey the players hold the puck, not a ball. But my frustration wasn't tempered by the fact that my teammates were holding vulcanized rubber instead of a rubber ball. Nothing irritated me more than seeing the flow of the game ruined by a player who wanted to skate with the puck instead of pass it to open teammates or to open areas of the ice, areas soon to be filled by streaking teammates eager to get a lead pass.

A similar blindness may affect club tennis players. When I see players fail to hit the ball into the open court, or fail to move offensively or defensively in response to the evolving action within points or matches, I wonder if this might be a lack of tennis vision that I'm seeing. Perhaps players are so caught up in hitting the ball that they don't see the game as good players see it.

Monday, April 25, 2005

Winning at a Loser's Game

In 1970 a scientist named Simon Ramo wrote a book called Extraordinary Tennis for Ordinary People. In his book, Dr. Ramo reported the results of a statistical study he did of tennis matches. Dr. Ramo found that at the elite level (top college and professional players), 80% of points were won (by forcing errors and hitting winners) while at all other levels, 80% of points were lost (by committing unforced errors). Therefore, he said, at the elite level tennis is a Winner’s Game and for the rest of us, tennis is a Loser’s Game, that is the outcome of the match is determined by the actions of the losing player.

Since very few of us play at the elite level, how can we win at a Loser’s Game? Well the obvious answer is to reduce your unforced errors. Given a chance your opponent will probably make enough errors to hand you the match. But the obvious answer isn’t necessarily the complete answer. While reducing your errors will allow you to beat many more of your opponents, it won’t be enough to beat one particular kind of opponent – the retriever.

The retriever has been playing error-reduction tennis his whole life. So if you simply commit to missing fewer shots you’ll win more matches, but you’ll probably still lose to the dedicated retriever. The matches will just take longer.

So short of bombing serves like Roddick, serve and volleying like Rafter, or pounding winners from the mid-court like Agassi, how the heck to you beat these players? The answer is to follow these three steps:
Step 1: Be consistent from the baseline

This means hitting mostly deep, solid crosscourt ground strokes, with the occasional short angle mixed in if you have those shots in your arsenal. Above all you must be patient. Trying to end the point from the baseline is a recipe for quick failure.

Step 2: Take advantage of shots your opponent hits short

This means attacking at your first opportunity – starting with weak second serves and any subsequent shot that lands short in your court (as long as it doesn’t pull you wide into the alley). This attacking approach shot should be driven toward your opponent’s weakness (or down the nearest line if you’re just inside the singles sideline), ideally cornering your opponent. Again, short angles are good here, too, if you have those shots.

Step 3: Finish!

This means moving forward and ending the point with solid, angled volleys and smashes hit either to the open court or behind your fast-moving opponent. The better your approach shots are, the easier this final step will be.
As Dr. Ramo found, many of your opponents will beat themselves if you just give them the chance. For those stubborn foes who won’t, it takes considerable practice, patience and skill to finish the job yourself. But if you follow this three-step recipe, you too can win at a Loser’s Game.

Wednesday, April 13, 2005

Bill James

I just finished reading an interesting interview with Bill James. It's most interesting if you're a fan of baseball, of course. I'm a mild fan of baseball, but a big fan of James' analytical style.

Here's part of an answer from James regarding standardization:
Standardization destroys the ability to adapt. Take the high mounds of the 1960s. We “standardized” that by enforcing the rules, and I’m in favor of enforcing the rules, but suppose that the rules allowed some reasonable variation in the height of the pitching mound? What would have happened then would have been that, in the mid-1990s, when the hitting numbers began to explode, teams would have begun to push their pitching mounds up higher in order to offset the hitting explosion. The game would have adapted naturally to prevent the home run hitters from entirely having their own way. Standardization leads to rigidity, and rigidity causes things to break.
Awesome.

And here's James on complexity and ways of knowing:
I believe in a universe that is too complex for any of us to really understand. Each of us has an organized way of thinking about the world—a paradigm, if you will—and we need those, of course; you can’t get through the day unless you have some organized way of thinking about the world. But the problem is that the real world is vastly more complicated than the image of it that we carry around in our heads. Many things are real and important that are not explained by our theories—no matter who we are, no matter how intelligent we are.

I created a good part of the analytical paradigm that the statistical analysts advocate, and certainly I believe in that paradigm and I advocate it within the Red Sox front office. But at the same time, the real world is too complicated to be explained by that paradigm.

It is one thing to build an analytical paradigm that leaves out leadership, hustle, focus, intensity, courage and self-confidence; it is a very, very different thing to say that leadership, hustle, courage and self-confidence do not exist or do not play a role on real-world baseball teams.
I've chopped off the quote before James says what he really thinks of people who fall into the latter category.

Read the whole thing.

Thanks to the Hardball Times for providing the link to the interview.

Sunday, April 10, 2005

Can't Win

I'm watching the Masters golf tournament today. Lanny Wadkins just said that Tiger was playing defensively, trying to avoid mistakes. "When you're trying to avoid mistakes, that's when you make them," Wadkins said. "Definitely," agreed Bobby Clampett.

Of course, one of the themes of Masters week, and of major golf championships in general, is that when you get behind and have to play agressively, that's when the course will bite you. Phil Mickelson said that very thing about Augusta National last night.

So which is it? My guess is that Mickelson is correct and that aggressive play sooner or later will get you on tough golf courses. On what do Wadkins, Clampett and others base their opinion that playing defensively brings on mistakes?

Maybe commentators just have to have something to say to add to the drama and it doesn't really matter so much what they say, as long as they say something.

Wednesday, April 06, 2005

Half-Pipe Theory of Motor Skill

Drop a ball into a half pipe at your nearest skate park. What happens to the ball? It rolls down to the bottom of the pipe and then goes up the other side, stops, rolls back down to the bottom and back up the other side again. Pretty soon the ball will come to rest in at the bottom of the half pipe.

Now kick the ball lightly up the original side of the pipe. After some backing and forthing, the ball will again come to rest at the bottom of the pipe. Try it again, but kick it harder, this time up the opposite side first. Again after some backing and forthing the ball comes to rest at the bottom of the pipe.

As long as you don’t kick the ball hard enough for it to escape the half-pipe, the ball returns to the bottom of the pipe no matter which way you kick it or how hard you kick it.

Some motor control and learning researchers think your joints and muscles may act sort of like that half-pipe when it comes to motor skills. Over time you settle into a particular half pipe. For example after some experimenting, you learned to walk. Your particular gait represents your own special walking half-pipe. You don’t have to think about it at all. You just walk along and if you get bumped one way or the other, or if someone trips you (not enough to knock you down) after some backing and forthing, you resume your normal gait.

Your tennis game may be like this too. As players learn we form our own tennis half-pipes. The half-pipes constrain our stroking patterns. Initially it’s not too tough to move from one half-pipe to another. The walls are pretty low. Over time those walls get higher and steeper. It gets harder to kick your ball out to another half-pipe. Your strokes become grooved.

This is a good story with a dark side, or a bad story with a bright side, however you’d like to think of it. Once you settle to the bottom of a high-walled half-pipe, you can pretty much count on coming to rest at the bottom of that particular pipe. Take some time off. Play a lot. Take lessons. Whatever you do, your tennis strokes, after some backing and forthing, return to the bottom of the same old half-pipe.

For Andre Agassi, this is a very pleasant situation. For others it’s not so pleasant. Andre, no matter how much you bump him, returns to the bottom of a half-pipe that works very, very well for tennis. Others return to the bottom of half-pipes that don’t work so well for tennis. Maybe the bottom of one half-pipe swings across the ball rather than through it. Another half-pipe may tend to pull up too quickly on forehands. Try as you might to kick yourself out of that particular half-pipe (or however much you pay someone to kick you out of it), you seem to return to the bottom of the pipe. Sure you may get up the walls pretty far during a private lesson, but all too quickly, after some backing and forthing, you return to the bottom of the same half-pipe.

So why is this good news? Because if you’ve been playing for a while, you can probably count on your strokes to be “grooved” in their half-pipes. You can count on them. They are not fragile. The game would be very, very difficult if every time you went out to play you never had a clue which half-pipe you were in. This isn’t to say that you’ll always play well. Playing well is a different story. What I’m describing is your stroking pattern. Your motor control.

The bad news, as I alluded to before, is that improving (moving to a “better” pipe, a pipe more in Agassi’s neighborhood) is very difficult. To get up the wall, out of one pipe and into a better pipe takes tremendous energy. This can be very frustrating because you can practice, take lessons, and work on your strokes with tremendous energy, only to find yourself, after some backing and forthing, still at the bottom of the very same pipe. Someone else may not work at their strokes at all and sure enough, they also return to the bottom of their half pipe. You work at your strokes. They don’t. Yet you both have not permanently changed your strokes. Talk about frustration.

This isn’t to say that your half-pipe is permanent. With focused practice it is possible to get out of one pipe and fall into another one. Some people may be better at scaling the walls than others. Some people’s pipes may have lower walls than others. Whether you’ll succeed at moving to another half-pipe will depend upon many factors, mostly unknown at this point, at least unknown to me.

My hope is that as instructors we can come up with more effective ways of helping people go from one half-pipe to a better one. There’s no reason to think that’s not possible.

Sunday, April 03, 2005

One Up and One Back

Is there anything to be said for the much-maligned doubles formation known as one up and one back? Can players at any level win using this formation? Are players using this formation condemned to the lower rungs of the tennis ladder?

After seeing Virginia Ruano-Pasqual and Paula Suarez play at Wimbledon a few years ago, I began to question the conventional wisdom that players could not succeed with the one up and one back formation. Right there on the TV, before my very eyes, I saw two women playing in the Wimbledon finals with one player at the net and her partner on the baseline pounding groundstrokes. Neither of the two served and volleyed, nor did they come to the net after returns of serve. I had always been told and always thought that a defining characteristic of better doubles teams was that both players came forward every chance they got, that doubles was played, and more importantly doubles was won, at the net.

This observation was not comfortable for me. I had taught players of all levels to serve and volley or at the very least get to the net at the first reasonable opportunity when playing doubles. If the players were toward the lower end of the tennis ladder, my message was that if they wanted to move up they had to learn to get to the net, to serve and volley. Sure it was tough for them, but if they ever wanted to play better doubles they had to master the transition from the back of the court to the front of the court.

Or did they? Here were Ruano-Pasqual and Suarez succeeding at the highest level of women’s tennis violating this most holy principle. It began to look to me like the serve and volley players, the doubles players who chipped and charged behind returns, were being squeezed from both ends. The lesser players played one up and one back and so did two of the best women in the world.

I began to look around. Sure enough, the winners of local tournaments, the terrors of local leagues at almost all level played a lot of one up and one back. Hmm. Not all, of course. There were still a lot of net crashers winning, but it was hard to claim that one up and one back could not succeed based upon what I saw. I also noticed that many of the best women college players were using the one up and one back formation, too. Hmm. Maybe this craze was confined to top women players, but was not afflicting the men.

Then came the 2004 Athens Olympic Summer Games. Nicolas Massu and Francisco Gonzales of Chile won the gold medal in men’s doubles. They won the gold medal playing one up and one back. Dagger. The dreaded one up and one back system could now claim a major victory in men’s tennis, too. Oh sure, you could claim that this was an unusual event, that most top doubles teams do not pair two players from the same country and therefore the field at the 2004 Olympic Summer Games was weak. Fair enough. But it wasn’t that weak. There is simply no denying that a duo of men from Chile won the Olympics playing in the much-maligned one up and one back formation.

This does not mean that the one up and one back style is necessarily the best formation for everyone or for any specific team. What it does mean is that one up and one back is a valid, successful formation for a significant subset (the majority?) of all tennis players.

In the winter and spring of 2004, my eyes open and with the preceding evidence (with the exception of the 2004 Olympic Summer Games), I set out to investigate just what was behind the success of the one up and one back style. My investigation began with an analysis of the doubles played by my adult tennis students (a couple of dozen adult men and women, NTRP 3.0 - 4.0). Not just a casual observation, but with specific, detailed charting of their points.

My first step in learning about the doubles play of my students was to find out how long their points tended to last and how their points tended to end. To find out how long the points lasted I simply counted the total hits during each point. An ace, service winner, or a double fault was a one-hit point. A service return unforced error, winner, or forceful enough shot to cause an error was a two-hit point, and so forth. That took care of finding out how long their points lasted.

Wanting more information than that, though, I also put a mark on my court diagram indicating the position of the player hitting the final shot in each point. A blue mark indicated a winning shot (winner or shot directly forcing an error from the other team) and a red mark indicated an unforced error. This chart gave me a picture of where the hitter was when the point ended and allowed me to see pretty quickly which areas were more likely to produce winners and which areas were more likely to produce unforced errors.

So what did I find? The graph below (Fig. 1) shows the point lengths, measured by total hits. The left-most column, representing the first hit (serve), shows that 100% of points included the serve. Of course this must be true since all points begin with a serve. The second column, reaching a height of just over 90%, shows what percentage of points included a return of serve. What the 90% figure means is that roughly 10% of the points ended with an ace, service winner, or more commonly a double fault.

Figure 1



Column three shows that less than 70% of points last to the third hit. Put differently, over 30% of points end with the serve or with the return of serve.

As you can see, the probability of a point lasting until subsequent hits drops off sharply. Over half of all points played do not get to the fourth hit (receiving team’s second hit), and less than 10% of all points played went beyond six hits (three per team).

So the points tend to be quick. But how do the points end? Errors. The chart below (Fig. 2) shows how all the points ended, with the red column height indicating points that ended with a unforced errors and with the blue column height indicating points the ended with winners.

Figure 2



Clearly the total number of errors (the red columns) outnumbered the total number of winners. The ratio of errors to winners was roughly three to one for serves and returns of serve. The number of errors was still very large for the third hit, but we see that the winners also began to climb in that third column. The most common point played ended with an unforced error on the return of serve (red bar representing over 80 points). The second most common point played ended with an unforced error by the serving team (red bar representing 60 points). This latter data point is particularly relevant as we examine the wisdom of playing a serve and volley style.

Having learned how long my players’ doubles points lasted, and whether those points ended in unforced errors or in winning shots, I turned my attention to where the last hitter of the ball was on the court when he or she hit the last shot. To do this, I looked to my court diagram with red and blue marks on it. In order to make sense of the marks, I divided the court into three areas: the back court, the transition zone, and the finishing zone. I defined the back court as the area from a step inside the baseline to the back fence. I defined the finishing zone as the area about two steps inside the service line to the net. I defined the transition zone as the area between the back court and the finishing zone.


The chart below (Fig. 3) presents the number of errors (in red) and winners (in blue) from each of the three court areas.

Figure 3



The numbers of errors and winners in Figure 3 do not include serves and returns. In the back court, the number of both errors and winners is low. In the transition zone, the number of errors is very high, and the number of winners is relatively low. In the finishing zone the ratio switches, with winners outnumbering errors.

From this information, it looks like playing balls from the transition zone is a bad idea and that playing balls from the finishing zone is a good idea. But without knowing the total number of hits per zone, it is unclear just how bad and good those ideas are. To answer that question I had to go to video tape.

By video taping the doubles sessions and capturing every hit I was able to expand my knowledge of the playing characteristics to include error and winner rates. The first graph below (Fig. 4) shows what court area all the shots (exluding serves and returns) were played from.

Figure 4



The vast majority of shots were hit from the transition zone. That may explain the large number of errors hit from that zone in Figure 3 above. Having the number of total hits and the number of errors and winners from each zone, determining the error and winner rates was simple. The results of those caluculations for each area are presented below (Fig. 5),again with errors in red and winners in blue.

Figure 5



The error rate is the highest in the transition zone and the lowest in the back zone. The winner rate is the highest in the finishing zone and the lowest in the back zone.

What are the implications of the above data for doubles players and the formations they should assume, the court positions they should strive for, and the goals and responsibilities of each member of a doubles team?

The first implication is that players must avoid making errors in the first few hits of the ball. For the serving team that means getting a serve in on the first shot. Assuming the server gets the ball in, where should the server go? If the goal is to avoid making an error on the next shot, the place to go is nowhere. The server, as the above statistics demonstrate, should stay in the back court. An attempt to serve and volley will virtually guarantee the serving team’s second shot will be played from the transition zone if the net partner cannot pick off the return.

What should the receiving team do? Again, avoid an unforced error is the first priority since most doubles points (in this data set) end with an unforced return error. Aim the ball cross court and get the ball in play. Since an opposing player starts in the finishing zone, once the first priority of getting the ball in play is satisfied, the returner would be wise to avoid that player. The cross court return usually will do that. Having hit a good, cross court return, where should the returner go? Not the transition zone, that’s for sure. The best bet is to stay in the back court, letting the partner move into the finishing zone.

For both the serving team and the returning team, a player who starts back is well-advised to stay back. A partner who starts at the net, or in the transition zone, is well-advised to stay in the finishing zone or to move into the finishing zone. Hey. That’s one up and one back. Maybe that’s why this formation is so popular and so successful. It has a solid foundation in statistical reality.

With one player up and one player back, the responsibilities are divided quite effectively. The player who started back, serving or receiving serve, has the duty to get the ball in play, to keep the ball away from the opposing net player (in the dangerous finishing zone), set up his or her partner in the finishing zone with cross court drives, track down and return any lobs over the net partner, and lob over the attacking opponents if they both choose to come forward.

The player on each team who started in a forward position has the responsibility for staying in or going into the finishing zone and trying to pick off weak replies and put them away. Only the player in the finishing zone has a realistic option of hitting a winner. Therefore, that person should look for and seize opportunities to hit winning shots for his or her team. Most points in tennis are lost and not won, but if they are to be won, the vast majority of the winners will be struck from the finishing zone.

Does all this mean that no player should ever serve and volley in doubles? Not at all. If a player has very good mid-court volleys relative to his or her ground strokes and lobs, or if a player has very good mid-court volleys relative to the opposing returns, then it may be wise to serve and volley. If the opposing team cannot or will not lob, then it also may make sense for a doubles team to get both players into the finishing zone. However, it is probably wise to come in behind a higher shot giving the back player the chance to advance through the transition zone without having to hit a ball there.

Agile players with devastating volleys and smashes may also want to get to the net as often as possible. But if you don’t list hitting scissors-kick overheads, chasing down lobs and hitting winners between your legs among your strongest shots, perhaps you should consider the wrongly-maligned one up and one back doubles formation. If you decide it’s for you, you’ll be in very good company.

Friday, April 01, 2005

The Modern Forehand

Much has been made of the differences in technique between the classical forehand and the modern forehand. My contention is that the two methods of hitting a forehand have more in common than they have differences. I also contend that the differences, and there are differences, stem from one primary cause: increased raquet-head speed.

Before comparing and contrasting the two forehand techniques, I will present one example of each method. The first QuickTime movie below is an example of a classical forehand. The player below is using an Eastern Forehand grip.



To view the video click the play button (the filled in arrowhead on the left below the picture). If you would like to view the movie frame-by-frame, which will be useful at times, you can do so using the left and right arrow buttons on your keyboard.

In the next movie, the player is hitting a modern forehand using a Semi-Western (or perhaps Western) Forehand grip.



[Modern forehand video from EASI Tennis]

So, what are the similarities? What are the differences?

In both cases shown above the players drive with the front leg (left leg since both players are right handed). In both cases the players appear to be shifting their weight onto the drive leg in the early portion of the forward swing. The extension of the drive leg causes both players to move upwards slightly coming into contact, violating the old axiom that players must stay down when hitting ground strokes. In both cases the hips rotate so that the right hip moves counter-clockwhise toward contact. In both cases the shoulders turn away from contact in the backswing, and rotate toward contact in the forward swing. Both players are applying moderate topspin. After contact, both players let their racquets continue to move through the ball and finish around to their non-hitting side.

That doesn't exhaust the similarities, but it's a start.

What about the differences? Well, as I mentioned, the grips appear to be different, eastern for the classical stroke and western or semi-western for the modern stroke. The different grips cause different racquet face orientations at the end of the backswing. The eastern forehand grip leaves the strings in an open position, while the more western grip causes a closed racquet face. The classical player makes contact with an almost straight arm, while the modern player makes contact with a bent elbow. Notice also that the contact point for the classical player is lower than it is for the modern player. Though the contact was lower for the classical player, the racquet finishes the follow-through phase of the swing higher than the modern player's racquet.

So those are some of the differences. Again, the list is far from complete. Frequently one of the differences between the classical and the modern forehand that observers point out is the different stances. At one time I was fixated on that difference. I spent many an hour watching tour-level tennis looking for players who did not hit with an open stance. Having to wait so long led me to conclude that the open stance was a fundamental of the modern forehand. As you can see from the video above, I was wrong. The modern player above is clearly stepping into this particular forehand. It turns out that both classical and modern forehands can and are hit with both square and with open stances. There are differences in square and open stance methods, but those differences are not unique to either the classical or the modern forehand.

In the intro to this post I suggested that the reasons for the differences between the classical and the modern forehands stem from higher racquet-head speed. The leg drive of modern players (frequently forceful enough to lift them off the ground) and the rotational speed of modern players clearly exceeds that of players of the 1970s and earlier. The result of the increased leg drive and rotational speed is greater angular velocity of the racquets as they contact the ball. This causes fast ball speeds.

In order to control the racquet at these higher speeds, it is helpful to have the racquet lined up with the body in the fashion seen in the bent arm modern forehand. The bent arm also heightens the contact location which increases the size of the acceptance window through which the ball must be hit to clear the net and to fall back into the court. Another thing that increases the size of the acceptance window is topspin. The western and semi-western grips so common in the modern forehand allow for greater spin to be applied to the ball. The grips facilitate more top spin by allowing the player to take advantage of forearm rotation (pronation) to increase the vertical component of racquet-head speed.

As more players hit with high ball speed and with top spin, players must learn to return balls that they will strike at higher contact points. Those higher contact points lend themselves to more western grips. This becomes a positive feedback cycle where player A uses a lot of rotation, high racquet head speeds, western grips and topspin which causes his opponent, player B, to use more leg drive, more rotation, more western grips and more topspin. The evolution of the forehand proceeds with this positive feedback loop so that we see most players using "extreme" grips, a lot of body rotation, bent arms at contact, a lot of topspin, and full, free follow-throughs.

It is possible that someone who uses slices to keep the ball low could prove a difficult foe for players using the modern forehand technique. Time will tell what the next "modern" forehand will look like.