RA / Stiffness
Also known as: racquet stiffness, flex rating
RA is a racquet’s stiffness measured by how much the frame deflects under load. Higher RA (66+) means a stiffer, more powerful but harsher frame; lower RA (under 58) flexes more for feel and arm comfort.
Stiffer frames return more energy (more power) but transmit more shock, which can aggravate wrist and elbow issues in players with imperfect mechanics. More flexible frames absorb shock and offer more feel at some cost to raw power. RA interacts with string choice and swingweight, so it is one input into a full racquet setup rather than a standalone good/bad number.
Example
A player with elbow soreness drops from a 69 RA frame to a 62 RA one to reduce shock without losing much control.
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