Tuning and customization

The ratio between a racquet's gravitational moment and its inertia. The formula, one worked example, what four grams do to it depending on where they go — and the three things it does not say.

The same gram does not do the same thing at 12, at 3 and 9, at the throat or in the handle. What each position changes about mass, balance, swingweight and recoilweight.

A pro stock promises one simple thing: escape the retail frame. The promise is real. What is less real is the condition it arrives in, and the settings it carries — someone else's.

Racquet rankings contradict each other from one site to the next, and it is not dishonesty: the question is asked at a scale where the answer does not exist.

A racquet's size is not the child's age. What actually decides: length, mass relative to the arm, and the string — in that order.

Two frames from the same box can differ by several grams and several points of swingweight. What that gap costs in a match, and how it is removed.

Twenty-seven inches for everyone is a convention, not a law of physics. What half an inch moves on swingweight, reach and timing.

Our logo is a cubic tennis ball — a set of axes. It's how we name our racquets and how you find yours. X, Y, Z explained, and how the axis leads to a full frame + setup + string.

“Go lighter, it'll be easier” is the most common racquet advice, and one of the least tested. What a well-placed mass actually changes, with the figures.

Your ranking is not a physical quantity. How mass, balance and swingweight are chosen from a collision rather than from a level.

Head size, string pattern, stiffness, inertia: the reading keys tour technicians use, and what they say about your gear.

Mass, balance, swingweight, twistweight, MGR/I: the quantities that decide what a stroke costs, and the formulas to work with them.

ProSetup is not a racquet range: it is a tuning applied to the frame you already own. Mass, balance, swingweight, measured before and after.