How to choose a tennis racquet: weight, balance, swingweight

Read three numbers. Then pick the frame.

Key facts

1
A lighter racquet isn't automatically easier to swing, because its swingweight can be unchanged or higher.
Brody, Cross & Lindsey, The Physics and Technology of Tennis (2002)
2
The effective mass of a racquet at impact is about half its real mass at the centre of the strings and about a third near the tip.
Brody, Cross & Lindsey, The Physics and Technology of Tennis (2002), p.128
3
Serve speed with a wood racquet and a graphite racquet differs by under 5 %.
Brody, Cross & Lindsey, The Physics and Technology of Tennis (2002), p.176
4
By one textbook estimate, a 25 % wider head, from 8 to 10 inches, resists twisting on off-centre hits by more than 50 %, because twistweight scales roughly with width squared.
Brody, Cross & Lindsey, The Physics and Technology of Tennis (2002), p.201
5
The 1976 Prince oversize head was more than 50 % larger than the standard wood head of about 65 square inches.

Why it works

Mass is what you carry. Balance is where you carry it. Swingweight is the resistance to rotating the frame about your hand, and it depends on both. A frame of about 340 g with its mass in the head swings like a heavier one. The same mass in the handle whips.

Twistweight is the same idea about the racquet's long axis. It decides how much an off-centre hit turns the face. Mass far from that axis, as in a wider head or lead tape at 3 and 9 o'clock, resists the twist.

Every spec is a trade. A lower swingweight accelerates faster but gives less plow-through and more shock. A higher one comes round slower but brings more frame power, stability and less shock. Around 325 and up reads as stable. There's no best spec, only the one your swing can use.

The line to say on court
“Mass, balance, swingweight. The paint decides nothing.”

Drill: The three-number check

20 min · alone or with a partner

Weigh your strung racquet on a kitchen scale. Find its balance point on the edge of a ruler. Write both on the grip tape.
Look up the swingweight for your model and write it beside them.
Hit twenty forehands with your frame and twenty with another one. Note which came round slower and which twisted on mishits, then check your notes against the numbers.

Number to beat3 of 3 numbers written on the grip tape

Faults and fixes

Buying by weight alone

A light frame can swing heavy if the mass sits in the head.

FixAsk for the swingweight.

Believing stiff means free power

Stiffness trades comfort, and the evidence on shock is unsettled.

FixTry before you buy and watch how your arm feels.

Copying a pro's retail frame

Nearly every tour frame is a customised version of a retail mould.

FixMatch the specs to your swing, not the paint.

Adding lead tape without a plan

Lead at 12 o'clock and lead at 3 and 9 move different numbers.

FixDecide which number you want to change before you tape.

Questions players ask

What is swingweight in a tennis racquet?

It's the resistance to swinging the frame around your hand. It depends on both mass and balance, and it's what your arm actually feels.

Is a lighter racquet easier to swing?

Not necessarily. If more of its mass sits in the head, its swingweight can be the same as or higher than a heavier frame.

Does a stiffer racquet cause arm pain?

The sources disagree. Some say stiffer frames transmit more shock, while Brody, Cross and Lindsey say stiffer frames reduce hand shock and stiffer strings raise it.

Where should I put lead tape on my racquet?

At 3 and 9 o'clock to raise swingweight, twistweight and stability, or at 12 for more power. Tape in the handle restores a head-light balance.

What this doesn't cover

Stiffness and comfort are individual, and the sources disagree on whether stiffer frames cause more or less shock. There's no best spec: every number is a trade. Pick the frame your body can swing first. String and tension come after.

Sources

Tennis Warehouse University: Weight, Balance and Swingweight
Tennis Warehouse University: Hitting Location, Twistweight and Spin
Tennis Warehouse University: Effect of Racquet Customization
Brody, Cross & Lindsey, The Physics and Technology of Tennis (2002)

StrikeHow string tension and type affect spin in tennisSpin comes mostly from string snapback, not tension. During contact the main strings slide sideways and snap back as the ball leaves, adding rotation. Slick polyester slides further than nylon and, in one test, gave roughly 20% more spin. Tension barely changes ball speed, so a steeper swing path is the bigger fix. Strings also lose tension from the first minute.StrikeWhere is the sweet spot on a tennis racquetA tennis racquet has at least three sweet spots, centimetres apart. The vibration node gives the cleanest feel, the centre of percussion gives no jolt to the hand, and the maximum-rebound point gives the most ball speed. They don't coincide. Hit off-centre and the frame twists, the ball loses speed, and a shock runs to your wrist and elbow.Know the gameHow tennis racquets and strings changed the gameRacquets changed what players could forgive, and strings changed what they could swing. Bigger heads, up from about 65 square inches on wood, bought forgiveness on off-centre hits. The decisive change was polyester string: Gustavo Kuerten won Roland Garros with it in 1997, and the dipping, heavily spun passes it allowed helped make the net a losing position.StrikeWhy off-centre hits hurt your arm, and how to find the sweet spotOff-centre hits hurt because the frame twists and rings instead of moving back as one piece, so the ball leaves slower and the handle jolts your hand. The tendons that hold the wrist up catch that jolt, and a late backhand makes them work hardest. Fix the contact point first, then the string, then the frame.