What the numbers are
Every racquet in the database carries five ratings — power, spin, control, comfort and swing feel — each on a 0 to 100 scale. They come out of one formula applied to every frame, not from a person deciding each racquet in turn.
The inputs are lab measurements. Tennis Warehouse University measures racquets on an RDC machine and publishes the results: strung swingweight, flex, twistweight, ACOR power potential, vibration frequency and sweet-zone size. Those figures, blended with each frame's published specs, are what the five ratings are computed from. Where a number disagrees with your own experience of a frame, your experience is the better evidence — but it should not disagree with the other numbers on this site, and that is what the formula is for.
The scale is absolute, not a curve. Every input is normalised against fixed anchors — RA 54 to 74, swingweight 285 to 340 kg·cm², and so on — and every rating is mapped through fixed constants. Adding a racquet to the database does not move anyone else's score, and a control rating means the same thing next year as it does today.
Ratings land between about 20 and 95, and the ends are real frames rather than a clamp. The lowest power rating in the database is the Prince Phantom 93P (2021) at 22 — a 93 in², 18/20, 337g frame that is built to do exactly that. It means “the least free pace of anything listed here”, not “no pace”.
What goes into each rating
Nine inputs do the work: TWU's measured flex, swingweight, twistweight, vibration frequency, sweet-zone size, strung weight and strung balance, plus the frame's head size and string pattern. Each rating weighs them differently. Where two frames measure the same but every reviewer reports otherwise — an aerodynamic beam, a damping system — a correction of at most 8 points is applied, and each one is written down with its reason in the script that generates the ratings.
POWER
How much pace the frame returns on its own — how far the ball flies when you do not swing hard.
- Frame stiffness — TWU’s measured strung RDC flex blended with the published unstrung RA, together the largest input
- Head size — a bigger, more elastic stringbed returns more energy
- String pattern — open patterns launch higher than dense ones
- Swingweight, inverted — a 332 kg·cm² frame does not hand you free depth, you have to swing it
- Strung weight, inverted — the same reason, on a smaller scale
SPIN
How readily the frame generates topspin and slice — bite on the ball, and how much the stringbed helps you brush up.
- String pattern — the strongest single input; 16 mains bite and snap back more than 18
- Balance (measured strung) — head-heavy frames swing on a longer arc, which favours brushing
- Head size — a longer main string moves more, then snaps back harder
- Frame stiffness — firmer frames hold the string plane more predictably at speed
- Swingweight and weight, inverted — a frame you can accelerate brushes faster
CONTROL
How predictably the ball goes where you aimed, especially when you swing hard. Broadly the inverse of power, and computed that way, so no frame can score at the top of both.
- The power rating, inverted — half of this score
- Swingweight — mass through the ball resists being knocked off line
- Head size, inverted — smaller heads have a tighter, lower-launching stringbed
- Twistweight — TWU’s measure of how well the hoop resists twisting on off-centre hits
COMFORT
How the frame treats your arm — impact shock and harshness on off-centre contact, not softness of feel.
- Vibration frequency — TWU measures each frame in Hz; a lower number is a softer, slower impact
- Frame stiffness — the other half of this rating; see the table below
- Sweet-zone size — a larger measured sweet zone mishits less punishingly
- Strung weight — mass absorbs shock that a light frame passes to your arm
SWING FEEL
How heavy the frame feels to swing, not what it reads on a scale. This one is close to a direct readout: it is TWU’s measured swingweight in kg·cm², plus a little twistweight for how the mass is spread across the hoop, mapped onto 0-100.
- Swingweight, measured by TWU on the strung frame
- Twistweight, which decides how far out from the axis that mass sits
Power and control pull against each other by construction — half the control rating is the power rating inverted — but they are not a fixed trade-off. The two summed range from 107 to 129 across the database, so a frame can genuinely be better or worse than another at both.
A worked example: stiffness and comfort
Frame stiffness drives the comfort rating harder than anything else. Grouping every racquet in the database by its RA and averaging the comfort ratings shows the relationship plainly. These figures are computed from the live data on page load, so they always describe the current database:
- RA 54-59 — very flexible — 2 racquets, average comfort 88
- RA 60-64 — flexible — 30 racquets, average comfort 67
- RA 65-69 — medium-firm — 26 racquets, average comfort 51
- RA 70+ — stiff — 6 racquets, average comfort 44
The trend is monotonic, but stiffness is only half of the comfort rating. The Wilson Clash 100 v3 (2025) rates 92 for comfort at RA 54; the Babolat Pure Aero Rafa Origin (2023) rates 44 at RA 73. Between them sit frames that deviate from the trend because TWU measured them vibrating faster or slower, or with a larger sweet zone, than their stiffness number alone would predict.
Compare two frames at the extremes. The Babolat Pure Drive (2025, Gen 11) — 100 in², RA 72, 300 g, 320 mm balance, 16/19 — is a big, stiff, head-heavy, light, open-patterned frame: every input points at power, and it rates 87 power against 35 control. The Head Prestige Pro (2023) — 98 in², RA 60, 320 g, 310 mm, 18/20 — inverts each of those, and rates 81 control against 31 power. Neither frame is better. They are opposite answers to the same question.
How strings are rated
Strings are not scored on the same absolute scale as racquets. Each of the 30strings in the library carries a set of deltas — how far it shifts a racquet's power, spin, control and comfort away from a reference setup. That reference is a mid-priced synthetic gut at mid tension, which is also the stringbed a racquet's own ratings assume. This is why the synthetic guts in the library sit near zero on every axis.
The deltas are ordered by family before they are given values, so the set cannot drift into incoherence:
- Power— natural gut > multifilament > synthetic gut > soft polyester > firm polyester. Polyester is the lowest-powered family, so polys carry negative power deltas.
- Comfort — ordered by measured dynamic stiffness in lb/in from Tennis Warehouse University, cross-checked against their playtester comfort scores.
- Spin — shaped and textured polyesters highest, smooth multifilaments and natural gut lowest.
- Control — broadly the inverse of power; firm polyesters highest, natural gut lowest.
Construction type and gauge are real manufacturer facts, not estimates. Note that most strings ship in several gauges — the diameter listed is the most commonly stocked one, not the only option.
Selecting a string on a racquet page adds its deltas to that frame's base ratings and clamps the result to the 0-100 range. It is a directional model of a real interaction, not a prediction of what a specific setup will feel like at a specific tension.
Specifications and quotes
The specs shown on each racquet page — string pattern, balance, stiffness, head size, release date, unstrung weight — are published figures from manufacturers and established reviewers. They are nominal specs for the retail frame, unstrung, in the most common configuration.
Review quotes are excerpts from real, independently published reviews and verified-purchase customer reviews. Each one was checked against the live source page before it was added, and each is credited to its author and publication with a link. The database currently carries 219 quotes across 63 racquets, drawn from Tennis Warehouse University, Tennisnerd, Tennis.com, Perfect Tennis and verified customer reviews, among others.
No quote is fabricated, paraphrased and presented as a quote, or attributed to a professional player without independent verification that they said it about that specific racquet. Critical quotes are included alongside positive ones — where a frame draws consistent complaints, those appear too.
Racquet images are AI-generated representations, not photographs of the retail product. They are there to make the database scannable, and should not be used to judge a frame's cosmetics.
What these ratings cannot tell you
The honest limits, in the order they are most likely to mislead you:
- The inputs are measured; the weighting is ours. TWU measured the flex, swingweight, twistweight, vibration and sweet zone. Deciding that stiffness should count for 44% of a power rating is a judgement, and a different reasonable person would pick different weights.
- Eight of the frames here have not been through TWU’s lab, mostly 2026 releases. Their measurements are predicted by least squares from the specs of the 56 that have, and are flagged as modelled in the generating script. Treat those eight as the softest numbers on the site.
- A handful of frames carry a small manual correction, never more than 8 points, for technology the measurements cannot see — an aerodynamic beam, a damping system in the handle. Each one is listed with its reason in scripts/rebalance-stats.js.
- Manufacturer specs vary unit to unit. Two frames off the same production line can differ by several grams and a point or two of RA. Retail tolerance is real and the specs listed are nominal.
- Grip size, overgrips, dampeners and lead tape all change how a frame plays, and none are in the ratings. A frame set up your way is not the frame described here.
- They assume a mid-tension synthetic gut. Change the string and the numbers change — which is what the string slider on each racquet page is for.
- They do not know your game. A 45-power frame is not worse than a 90-power one; it is for a different swing. Ratings describe the racquet, not its fit for you.
Use the ratings to build a shortlist, then demo the frames on it. No spec sheet — ours least of all — substitutes for hitting with a racquet.
Corrections
If a spec is wrong, a quote is misattributed, or a rating looks indefensible against your own hitting time with a frame, send it over and it gets fixed. Corrections to published specifications are made on evidence; ratings are revised when the argument is better than the one behind the current number.
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Ratings are reviewed whenever a frame is added to the database or a new independent review of a listed frame is published.