Radar Guns 101

In this post, we’ll move forward from our ongoing discussion of talking about stroke speeds (or the lack of stroke speed, as the case may be) at the various levels of US Tennis to talking about a more basic issue: how to properly measure your stroke speeds in the first place.

The first thing you need to do is to measure your stroke speeds accurately. To measure your stroke speeds accurately, you need to get your hands on a good quality radar gun and understand how to use it properly.

Over the past two years, I’ve had the opportunity to use a large variety of radar guns from every price point that’s currently available from the under-$100 “budget” guns (i.e. Bushnell Speedster II) to the $1,400+ high-end guns from JUGS and Stalker. What I’ve learned from using these guns is that as long as you’re willing to spend at around $200 to $300 for a mid-price radar gun, there isn’t a noticeable difference in performance among the various brands, or between guns from different (i.e. higher) price points.

The price for radar guns is more-or-less open ended, and the more you pay, the more features you can get (direct download of data to your laptop, software analysis for the downloaded data, etc.). But the features that are available in the mid-range guns are more than enough for the purpose of getting accurate stroke speed measurements.

In my experience, you will only run into problems if you go the “budget” route and buy the lower-end guns such as the SpeedTrac/SpeedChek (the little black radar box you place in front of the net) or the Bushnell Speedster guns. The SpeedTrac/SpeedChek has improved since its original introduction in the mid-1990s, but when I use the SpeedTrac/SpeedChek side-by-side with a trusted mid-range or high-end radar gun, there is way too much difference in the measurements between the SpeedTrac/SpeedChek and say, the typical mid-range radar gun for me to trust the readouts of the SpeedTrac/SpeedChek.

IHMO, say no to the SpeedTrac/SpeedChek in all its incarnations because who knows what it’s measuring.

Likewise, I haven’t had a good experience using either the Bushnell Speedster guns—either one, Speedster I or II. The problem for me with Speedster I was that it couldn’t measure speeds over about 105 MPH very accurately (which doesn't fly when you work with high level competitive players who can serve over 110 MPH) and of course, when I read the “fine print” of the Speedster I specs, sure enough, it said that the measurement range topped out at 105 to 110 MPH for tennis.

Speedster II supposedly possesses improved technology compared with its ancestor, but still doesn’t seem to measure speeds over 110 MPH with great consistency or accuracy.

Therefore… IMHO, say no to the Speedster as well until further notice.

So, what radar gun do I recommend that performs without going overboard with either price or features?

The radar gun that I’ve found that has the best combination of performance and price/value is a relatively new introduction to the radar gun market called the Tracer SRA-3000 radar gun manufactured by Sports Radar, Ltd. (Homosassa, FL).

In side-by-side measurements with my high-end Decatur radar gun and a friend’s brand-new JUGS R1005, the Tracer, Decatur and JUGS guns perform identically when it comes to accuracy and consistency. The biggest difference between these two radar guns is that the Tracer is cordless (it runs on 6 AAA batteries!), and is much lighter than the Decatur (my Decatur is corded to a rechargeable battery stored in its carrying case).

The other difference between the Tracer and the Decatur and JUGS guns is the price. You can get a Tracer for around $180 retail, whereas the Decatur and JUGS guns will run you a minimum of $700 retail (new). That’s around a $500 difference in price for a radar gun that performs to the level of the “luxury” guns.

The performance and value of the Tracer that I’ve experienced is the reason why we decided to offer it for sale on the TennisSpeed website. It performs at a high level for a great price. What more can you ask for from any product?

OK, so now you have some idea about what the various radar guns on the market offer… So now you may be wondering how to use that radar gun to measure your stroke speeds.

Using the radar gun to get accurate stroke speed measurements is straightforward enough…

1. Mount the radar gun on a tripod (make sure you have a tripod mount on your gun… The Tracer has one, does yours?) to ensure that the gun itself is consistently aligned for each measurement—this makes for the most consistent measurements.

2. To get the most accurate measurements on groundstrokes, place the radar gun behind the contact point and place the tripod in straight line behind the intended flight of the shot. Make sure to set the height of the radar gun at the intended contact height of the stroke (i.e. if you intend to make contact at waist height, make sure the gun is also set on the tripod at waist height).

Therefore, if you want to measure the speed of your down-the-line forehand, a simple way to check that you’ve placed the radar gun in a straight line directly behind the path of the shot is to point the radar gun toward the area of the court where the forehand will land (Figure 1).

Figure 1. Radar gun positioning for down-the-line forehand (gun positioned in a straight line behind the path of the shot).

3. To get the most accurate speed measurements for your serve, set the height of the gun as high as your tripod allows. Place the tripod behind you in the same line as your hitting shoulder. Similar to the speed measurement for your groundstrokes, align the radar gun itself in a straight line directly behind the intended flight of your serve to obtain the most accurate measurement (Figure 2).

So, if you want to measure the speed of your slice serve, a simple way to check that you’ve placed the radar gun in a straight line directly behind the path of the shot is to point the radar gun toward the area of the service box where the serve will land in the service box.

Figure 2. Radar gun positioning for slice serve (gun positioned in a straight line behind the path of the shot).

When you follow these 3 simple steps, measuring your stroke speeds becomes a breeze.

Maybe now you are wondering about which strokes should you be measuring…

I have been measuring maximal serve and groundstroke speeds for my players in the same way the WTA measures its players to create its “Power Index”. I have been measuring maximal (and average) forehand, backhand, first serve, second serve and overhead speeds (of balls hit into play, of course!) in both training and live matches.

I have also been measuring so-called “rally speeds” where I measure the ball speeds during “neutral” groundstroke rallies (neither player is in an attacking or defensive mode/position). The “rally speed” of a player tells me a lot about what tactical options are available to a given player. And yes, there is a great difference in rally speed when comparing the various levels of competitive tennis from juniors and high school varsity tennis to college and professional tennis.

The difference in “rally speed” is quite similar (among US players) to the differences in serve speed that we’ve been talking about at some length in recent posts. That is, there is about a 25 to 30 MPH difference in rally speed between juniors and professional players.

To sum it up, go get your hands on a decent radar gun and remove all of the myth and mystery from your game. Measure your stroke speeds and create your own “speed profile”: average speed of your fastest forehand, backhand, first serve, second serve and overhead. Now you have a way to compare yourself to other players with known speed profiles to see where you really stack up…

Then, measure your “rally speed”, and when you finally look at the numbers… It will be a number that probably won't be keeping Roger, Rafa and Andy awake at night.

Don’t be surprised when you find out that your speed profile is well, more like a “slow profile”. Get it?

Starting with my next post, we’ll be getting into what you all have been waiting for…

We’ll start talking about how to increase the speed of the various strokes from a technical and conditioning perspective. And I’ll begin talking to you about one of the special projects I’ve been working on recently that has truly blockbuster potential in changing the way tennis technique is taught by coaches and learned by players.

So stay tuned…

TTFN!

How to make sense of the new WTA Power Index

In this post, I’ll take a short break from our ongoing discussion about how to improve your court movement to discuss an interesting speed-related event from the tennis world.

The event I wanted to mention was the launch of the “WTA Power Index” earlier this month at the final Acura Classic in San Diego. The point of the WTA Power Index is marketing—i.e. to give the fans a greater appreciation of the performance capabilities of the top female pros by highlighting how powerfully they strike the ball.

According to the official WTA Tour press release (8/8/07) explaining the Power Index:

“(I)t’s a great way (The Power Index) to recognize the extraordinary talent, athleticism, and sheer power of our top players… Other leading professional sports have introduced new methods to measure and compare the performance of their players to provide another level of insight to fans. The Power Index affords that same opportunity for women’s tennis.”

The WTA Power Index is calculated by taking the average speed of a player’s first serve, second serve, forehand, backhand, and overhead measured using the Hawk-Eye line-calling systems that are installed on all of the center courts of all the US Open Series tournaments.

And thus far, the most powerful player on the WTA Tour after the first three weeks of the Power Index is: (fanfare, please) Yaroslava Shvedova of Russia with an index of 102.9 MPH. Future Hall-of-Famer Venus Williams is second with an index of 98.8 MPH. Other notable (i.e. recognizable) names among the Top 10 players on the cumulative Power Index stats are Nadia Petrova (#4 at 97.4 MPH) and Elena Dementieva (#5 at 95.8 MPH).

Yaroslava Shvedova is the most powerful player on the WTA Tour? Hmmm… Shvedova isn't exactly a household name in women's tennis. She's not even one of the higher-ranked WTA players sitting currently at #74 in the official WTA Tour singles rankings.

In fact, there isn’t much of a correlation between the Power Index rankings and the actual WTA rankings. Look, the most powerful player in the short history of the Power Index, Shvedova, is currently ranked #74, and upon closer examination, 7 of the current Top 10 players on the Power Index are ranked outside the Top 25 of the actual player rankings.

I wonder how the WTA Tour is going to explain the inverse correlation between power performance and ranking performance?

Regardless of the Tour’s spin on the issue, I think that it shouldn’t surprise anyone that pure power isn’t necessarily a guarantee of match wins, especially among the women. Especially when you begin to notice that many of the biggest hitters among the WTA pros are not very adept movers on the court.

If you’ve been following this blog on a regular basis, you should understand by this point that slow court movement combined with big hitting is really a recipe for disaster from a high-performance perspective. Attempting to hit “big” with slow feet (you should also realize that there are many in the (pro) coaching establishment who preach that powerful stroking compensates for being a slow mover) is the classic, proven formula for maximizing unforced errors and makes it even more difficult to win any tennis match, especially one at the pro level.

Another detail to consider in explaining the disparity in the Power Index and actual player rankings is the fact that the women achieve those shot velocities with using far less (top-)spin that is essential to control such high-velocity strokes during play.

What this means is that while some WTA players may generate high shot speeds, they do so with far less control than their male counterparts on the ATP Tour. With far less spin on their shots (as in 50 to 70 percent less spin compared with the men on average) and therefore, far less control over their shots, the players who are top-ranked on the Power Index are, not surprisingly, also those same players with a proven reputation for generating large numbers of unforced errors during their matches.

Any tennis player who commits too many errors of the unforced variety is going to have a tougher time winning matches with any consistency. So when you begin to look at things more closely, it’s no real surprise that there isn’t a strong correlation between the Power Index rankings and the actual WTA rankings. The big hitters make way more errors during play and have a harder time winning matches consistently, so their rankings are lower.

I would be very interested to know what would happen if the WTA Tour could somehow introduce a “spin factor” into the Power Index—my prediction is that when spin production is part of the formula, the Power Index rankings will much more closely resemble the player rankings. And, yes, if you are wondering, with Hawk-Eye technology, it is possible to measure the spin rates of each shot struck during play.

Finally, I’ll make one final comment about the potential impact of the WTA Power Index… That is to say that tennis may be the one professional sport where the fans may achieve a greater insight into the quantitative aspects of the performance of their favorite players before the professional coaches who are paid the big bucks to train and prepare them.

Pro tennis coaches, by and large, do not pay much, if any attention to the quantitative aspects of the sport they are considered experts at. Sure they can recognize unusual physical ability—“talent”—when they see it, but they have almost absolutely zero idea about the quantitative details of the talent they observe.

Pro coaches generally do not know the speeds and spin rates or running times of their players. They consider these parameters to be unnecessary details mainly because they generally believe that the success in pro tennis is determined primarily, if not exclusively, by intangible factors such as “confidence” and mental toughness and motivation to perform hard work. They even believe that these intangibles can overcome the great majority of physical or technical shortcomings that a given player may have.

These beliefs are mainly based in the personal experiences of the great majority of coaches at the pro level, who were often former professional players themselves (with varying degrees of success). In the days when they were active players (typically in the 1970s and early 1980s), it was true that the psychological intangibles were paramount in determining a player’s ability to succeed on the tour because there was very little physical or technical separation between the pro players of that day and age.

Today, physical ability plays a far greater role in determining a player’s ability to succeed at the pro level, although the establishment continues to recite their deeply entrenched perception that the intangibles remain the most critical determinant of pro success. Today, racket speed and foot speed in particular create separation between the true pro contenders from the rest of those players toiling in the purgatory known as the Challenger and Futures circuits.

No matter how mentally tough and focused a prospective pro player may be, if he can’t consistently hit first serves over 125 MPH or can’t put a 130 MPH serve consistently back into play or retrieve a 95 MPH groundstroke slammed into the corners, no amount of mental skill and savvy can compensate for a lack of physical capacity.

This is the new reality of professional tennis…

Pro tennis has become essentially identical to other professional sports in that you must possess ultimate physical talent to succeed at the highest possible levels of the sport. Intangibles such as confidence and motivation remain as key factors in maximizing one’s competitive potential, but such intangibles can no longer compensate for a player’s physical shortcomings and athletic limitations (see Hingis, Martina).

TTFN!