How tennis racquets and strings changed the game

Tell the era from the racquet. Then say what it did to the swing.

Key facts

1
Switching from wood to graphite changes serve speed by under 5 %.
Brody, Cross & Lindsey, The Physics and Technology of Tennis
2
In 1997 Gustavo Kuerten, 20 years old and ranked 66th, won Roland Garros with a polyester string.
Tennis.com, "Kuerten's new string"
3
A 25 % wider racquet head gives more than 50 % more resistance to twisting, because twist resistance grows with the square of head width.
Brody, Cross & Lindsey, The Physics and Technology of Tennis
4
Dropping string tension from 60 to 50 lb adds under 1 % to ball speed.
Brody, Cross & Lindsey, The Physics and Technology of Tennis
5
With topspin of 20 revolutions per second, the range of launch angles that lands in grows from 4.1° to 6.4°, about 56 % more margin.
Brody, Cross & Lindsey, The Physics and Technology of Tennis
6
The ITF banned the spaghetti racquet on 13 July 1978, its first definition of a racquet.
ITF Rackets and Strings regulations

Why it works

The string bed is a trampoline, and the ball is a bad spring. Strings return about 95 % of the energy they store, while the ball loses about 45 %. So power was never the string's gift. Spin was. Polyester is stiff and slick: the main strings slide sideways and snap back. Because it's low-powered, players string it lower and swing harder.

Lower tension plus a faster swing means more topspin, and topspin widens the launch window. That's why the tour followed Björn Borg, who swung up on wood with a western grip years before the string arrived. It's also a big part of why serve-and-volley faded: dipping, heavily spun passes and returns made the net a losing position, though courts were slowed and balls made heavier in the same years.

Frames matter for a different reason. The Wilson T2000 steel frame came in 1967 at 67 square inches, the Prince oversize in 1976 with a head more than 50 % larger than wood, the Dunlop Max 200G in 1980 and the Wilson Profile widebody in 1987. A wider head resists twisting with the square of its width, so oversize bought forgiveness. Stiffer frames reduce hand shock, stiffer strings raise it, and frame stiffness sits roughly between 50 and 75 on the RA scale.

The line to say on court
“Racquets change what you can forgive. Strings change what you can swing.”

Drill: Date the racquet

15 min · alone

Collect ten photographs of racquets from different eras.
Read the head first: a small wood-era head of about 65 square inches, open-throat steel, oversize or mid-plus.
Read the throat and beam: wood laminations, a wire throat or a thick widebody beam.
Read the strings if you can: gut looks rough and natural, a monofilament looks smooth. If the photo can't tell you, trust the frame. Write a decade for each racquet, then check.

Number to beat8 of 10 racquets dated within a decade

Faults and fixes

Believing bigger racquets are the whole story

The string did more than the frame.

FixPut 1997 and polyester on the timeline first.

Believing more power killed serve-and-volley

It was spin-heavy, dipping passes, not raw pace.

FixWatch the pass dip, not the speed gun.

Believing equipment just makes serves faster

Wood to graphite changed serve speed by under 5 %.

FixLook at the swing path and the spin rate instead.

Questions players ask

Did bigger racquets kill serve-and-volley?

Not mainly. Polyester strings made dipping, heavily spun passes and returns that turned the net into a losing position. Courts were slowed and balls made heavier in the same years, so poly is a primary driver, not the sole cause.

Do polyester strings give more power?

No. Poly is stiff and low-powered. Its gift is spin: the strings slide and snap back, and players string it lower and swing harder.

Does a bigger racquet head give more power?

A bigger head mostly buys forgiveness. It resists twisting on off-centre hits, and that resistance grows with the square of its width.

Does lower string tension give more power?

Barely. Going from 60 to 50 lb adds under 1 % to ball speed.

What this doesn't cover

Whether strings, fitness or slower courts did most to change the game is still debated, so poly is a primary driver, not the only one. Head-size figures for the early oversize vary by source. Spin-string marketing is contested: snapback and low friction matter more than string shape.

Sources

Brody, Cross & Lindsey, The Physics and Technology of Tennis (2002)
Cross & Lindsey, "How Tennis Strings Go Dead," Tennis Warehouse University
Tennis.com, "Kuerten's new string"
ITF Rackets and Strings regulations
GB Tennis Museum on spaghetti stringing
International Tennis Hall of Fame racquet collections

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.StrikeHow to choose a tennis racquet: weight, balance, swingweightChoose a tennis racquet by three numbers: mass, balance and swingweight. Mass is what you carry, balance is where it sits, and swingweight is what your arm feels when you swing. A lighter frame isn't automatically easier to swing. If its mass sits in the head, its swingweight can be the same or higher. Ask for swingweight.Know the gameWhat is the Open Era in tennis, and why does 1968 matter?The Open Era is tennis since 1968, when the majors first let professionals and amateurs play in the same draws. Before it, the best players were barred from the majors for taking money. That's why records carry a start date: Margaret Court has 24 majors across both eras, and Serena Williams holds the Open Era women's record with 23.StrikeHow to hit topspin in tennisTo hit topspin, swing low to high so the racquet brushes up the back of the ball with a slightly closed face, instead of driving through it. The path makes the spin, not a wrist roll: the ball has left the strings before a rolled wrist closes the face. Polyester strings add a bonus on top of whatever spin your path makes.