Why do pros restring their rackets before every match?

Professional players require absolute consistency in their equipment. Co-polyester strings lose 10% to 15% of their tension within 24 hours of stringing (static loss) and lose elasticity rapidly during heavy hitting (dynamic loss). To ensure the launch angle and depth control remain identical across matches, pros play with frames strung fresh that morning.

Which is better in a hybrid setup: gut in the mains or crosses?

Putting natural gut in the mains and polyester in the crosses (like Federer and Djokovic) creates a softer feel, more comfort, and higher power, as the mains dictate the overall elasticity of the string bed. Placing polyester in the mains and gut in the crosses provides a crisper, lower-powered response with higher spin potential.

What string tension does Jannik Sinner use?

Jannik Sinner strings his Head Speed MP (customized) with Head Hawk Touch polyester strings. He typically strings his rackets at 28 kilograms (approximately 61.7 pounds) in the mains and 27 kilograms (approximately 59.5 pounds) in the crosses, which is on the higher end of the modern professional spectrum.

Do any ATP pros play with nylon strings?

No active ATP Tour professional plays with standard nylon or synthetic gut strings. The swing speeds at the professional level (often exceeding 85 mph) would cause nylon to stretch out instantly, lack the necessary control, and snap within minutes of play, making polyester or natural gut hybrid setups mandatory.

What is the lowest string tension used on the ATP Tour?

French veteran Adrian Mannarino is famous for using exceptionally low tensions. He strings his Babolat Pure Aero frames with Luxilon ALU Power between 10 and 12 kilograms (approximately 22 to 26 pounds). This ultra-low tension creates a massive trampoline effect, allowing him to block hard baseline shots with minimal effort.

What Strings Do ATP Pros Use? Pro String Setups

When watching professional tennis, it is easy to focus on the rackets. You see the paint jobs of the Wilson Blade, Babolat Pure Aero, or Head Speed spinning in the hands of the world's best. But there is an open secret among professional players, coaches, and tour stringers: the frame is just a shell; the strings are the engine.

If you strung Novak Djokovic's racket with cheap nylon strings from a department store, he would struggle to control his baseline drives. Professional players swing at head speeds exceeding 80 mph, producing immense kinetic energy. To keep the ball inside the lines, they require strings that generate massive topspin and predictable control.

In this guide, we will take you inside the pro locker room, explaining what strings ATP pros use, the technology behind co-polyester strings, the rise of the hybrid setup, actual pro setups, and the wide range of string tensions used on the pro tour.

1. The Dominance of Co-Polyester (Poly)

Walk through the stringing room at any Grand Slam, and you will hear the electronic pull of stringing machines working around the clock. Over 90% of ATP players play with co-polyester strings (often referred to as "poly").

Polyester is a stiff, single-strand plastic monofilament. Because it is rigid, it creates a low-powered string bed. This low power is exactly what pros want—it allows them to swing at 100% speed without worrying about the ball flying long. Additionally, polyester has a slick surface coating that allows the main strings to slide and snap back dynamically on impact, generating the heavy topspin that defines modern tennis.

The Most Popular Pro Polyester Strings:

Luxilon ALU Power: The undisputed king of the pro tour. Used by players like Carlos Alcaraz and Grigor Dimitrov, it offers a crisp, metallic feel with exceptional control.
Babolat RPM Blast: The octagonal, slick string made famous by Rafael Nadal. It is designed specifically for maximum snapback and spin.
Solinco Hyper-G: A bright green, square-shaped string favored by many college and rising ATP players for its bite on the ball.
Head Hawk Touch: A co-polyester string engineered to provide structural comfort and touch, used by Jannik Sinner.

As the United States Racquet Stringers Association (USRSA) notes:

"The modern pro game is defined by racket-head speed and spin. Stiff polyester strings allow players to swing at maximum velocity, generating the friction and lateral snapback necessary to produce spin rates exceeding 3,200 RPM."

2. The Hybrid Setup: Power Meets Control

While pure polyester provides spin, it is stiff and can cause arm fatigue. To balance control and comfort, many pros use a hybrid string setup (combining two different string types).

The most famous hybrid combination on tour is Natural Gut and Co-Polyester:

Natural Gut in the Mains (Vertical): Offers power, pocketing, feel, and comfort.
Polyester in the Crosses (Horizontal): Controls the movement of the gut, adds spin, and lowers the launch angle.

Roger Federer and Novak Djokovic famously popularized this setup. By placing natural gut (made from cow intestines, which is highly elastic) in the vertical main strings, they get a soft, comfortable feel and easy depth. By placing stiff polyester in the horizontal cross strings, they restrict the gut's movement, maintaining control.

Conversely, some players run a reverse hybrid (polyester in the mains, gut in the crosses) to get a firmer, spin-centric response with a slightly lower launch angle.

3. Technical Specifications: Famous ATP Pro String Setups

The table below details the actual racket frames, string models, tensions, and patterns used by top ATP tour players.

Player	Racket Model (Actual Mold)	Main String	Cross String	Main Tension (lbs/kg)	Cross Tension (lbs/kg)	String Pattern
Novak Djokovic	Head PT113B (Custom)	Babolat VS Touch Gut (1.30mm)	Luxilon ALU Power (1.25mm)	59.5 lbs (27 kg)	57.3 lbs (26 kg)	18x19 (Dense)
Carlos Alcaraz	Babolat Pure Aero 98	Babolat VS Touch Gut (1.30mm)	Babolat RPM Blast (1.25mm)	55 lbs (25 kg)	53 lbs (24 kg)	16x20
Jannik Sinner	Head Speed MP (Custom)	Head Hawk Touch (1.25mm)	Head Hawk Touch (1.25mm)	61.7 lbs (28 kg)	59.5 lbs (27 kg)	16x19
Rafael Nadal	Babolat AeroPro Drive (2005)	Babolat RPM Blast (1.35mm)	Babolat RPM Blast (1.35mm)	55 lbs (25 kg)	55 lbs (25 kg)	16x19
Daniil Medvedev	Tecnifibre Dynacore 305	Tecnifibre Razor Code (1.25mm)	Tecnifibre Razor Code (1.25mm)	48.5 lbs (22 kg)	48.5 lbs (22 kg)	18x20 (Dense)
Adrian Mannarino	Babolat Pure Aero	Luxilon ALU Power (1.25mm)	Luxilon ALU Power (1.25mm)	24 lbs (11 kg)	24 lbs (11 kg)	16x19

The International Tennis Federation (ITF) biomechanics research highlights that polyester's low elasticity is what makes modern baseline rallies possible:

"The introduction of polyester monofilament strings has shifted the tactical balance of tennis, allowing players to execute high-speed passing shots and baseline drives with a margin of safety that was mathematically impossible with natural gut or nylon."

4. String Tensions on the Pro Tour: The Modern Trend

There is a common misconception that professional players string their rackets at extremely high tensions to control the ball. While this was true in the wood racket era (when players strung natural gut at 65+ lbs), modern pro tensions are much lower.

Today, most ATP players string their rackets between 46 and 54 pounds. Lower tensions allow the polyester strings to slide and snap back, increasing spin and sweet spot size.

High-Tension Outliers

Dustin Brown: Has strung his rackets as high as 70 pounds to control his flat, fast-paced attack.
Pete Sampras: Famously strung his Wilson Pro Staff 85 with natural gut at 70+ pounds, requiring stringers to pull tension immediately before he walked on court.

Low-Tension Outliers

Adrian Mannarino: Strings his frames as low as 22 to 26 pounds. This creates a massive trampoline effect, allowing him to hit short-angled blocks and redirect pace with a very compact swing.
Jack Sock: Strung his rackets in the 35 to 40 pounds range to generate his loop topspin forehands.

5. Gauge Selection: The Thickness of the Engine

Pros are highly sensitive to the thickness of their strings, known as the gauge. Most tour players use:

1.25 mm (17 Gauge): The tour standard, balancing spin, durability, and tension maintenance.
1.30 mm (16 Gauge): Used by heavy spin hitters like Rafael Nadal (who uses a thick 1.35mm RPM Blast) to prevent premature breakage during long matches.
1.20 mm (18 Gauge): Rare on tour, but used by players looking for maximum feel and snapback on fast clay courts.

6. Summary Verdict for Recreational Players

While it is tempting to copy Jannik Sinner or Carlos Alcaraz, caution is required. Polyester strings are stiff and lose their playability within 8 to 10 hours of play.

Unless you are a competitive tournament player who swings at high speeds and breaks strings regularly, a pure polyester setup can lead to forearm strain and tennis elbow. For intermediate players, a hybrid setup (putting a soft multifilament in the mains and poly in the crosses) or a high-quality multifilament is a safer, more cost-effective choice that protects your joints while still providing excellent depth.