Tuning and customization

"Stable" means two things: not twisting when the ball is hit off-centre, and not being pushed back when it comes in heavy. Two figures measure them.

Balance is given in centimetres from the butt or in points from the middle. Both say the same thing, as long as you know where you count from.

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.