## Welcome to Racquet Research

This site is for the best available objective data on racquet performance and prevention of tennis elbow. No vague sales puffery, condescending jocularity, or subjective playtest results — just hard facts based on measurements and physics.

If the physics part sounds scary or boring, don’t worry. It isn’t necessary to know a lot of math and science to understand what’s presented here, and as you read, you may learn a lot in a fun way. For a short and simple summary of the main points, read The Complete Idiot’s Guide to Choosing a Tennis Racquet. For an introduction and overview of the technical issues, and a description of the criteria used for evaluation, please read Introduction to Racquet Science. You’ll learn there why these criteria are important:

You will also find here the answers to Frequently Asked Questions.

The Formulas for Racquet Performance are generalized in order that the evaluation criteria can be computed for any ball speed, racquet elasticity, etc. These formulas are general enough to be used for any eccentric impact situation, whether in tennis or elsewhere, such as golf or baseball. Derivations of these formulas are provided. Only high school algebra is required to understand the formulas and derivations. Basic physics is helpful but not necessary, because enough background is provided to learn basic mechanics and first year physics as you read.

To make possible meaningful and concrete comparisons of different racquet models, five benchmark conditions were established, with given ball speeds before and after impact, impact point 16 cm from the tip, a common axis of rotation on the stroke, and string tension, ball bounce, and racquet stiffness, etc. such that the coefficient of restitution is the same for all racquets (0.85). Formulas were applied, using the constants supplied by the benchmark conditions and the variable values given by measurements of the racquets, to get values under the performance criteria, then the rankings under the performance criteria were used to determine rankings under the macro criteria of Efficiency (how much speed for your effort), Elbow Safety, Shoulder Safety, Wrist Safety, and Dexterity (how easy it is to wield). Then the results under the macro criteria were combined to produce the Overall Rankings. The portal page for the 2002 rankings includes links to rankings on all criteria for each of the 167 racquets in the survey. To find out how your racquet ranked, click here. For new racquets not yet included here, you can use the published racquet specs in an easy formula that will give you a fairly reliable index of racquet quality.

One result of applying the principles discussed here to racquet customization can be found in the superior performance of a Wilson Hammer 6.2 95 extended an inch by a heavy butt cap. To see these results, click here. There are two guides for racquet customizers: how to calculate the shift in balance resulting from adding weight, and how to match two racquets so that their weight, balance, and swingweight are the same.

Data used for evaluations and ranking are from published measurements done by the technicians of the US Racquet Stringers Association (USRSA), for strung and gripped racquets. Now go to the Introduction.

Racquet manufacturers are invited to send accurate strung and gripped racquet data, or other information, for inclusion in future updates. Players and researchers are cordially invited to correspond.