Most tennis players obsess over rackets.

Almost none understand their strings.

That’s a problem — because your strings are the engine of your game.

They determine:

• Ball trajectory

• Depth control

• Feel and touch

• Spin generation

• Injury risk

• Confidence under pressure

And yet most players choose strings based on habit, brand, or what a friend recommended.

In this guide, we break down:

• The three main types of tennis strings

• How string tension really works

• Why high tension does NOT mean more control

• How surface and weather affect tension

• Why string color changes performance

• What you can learn from Ash Barty and Aryna Sabalenka’s setups

• The biggest myths about spin and shaped strings

All insights in this article are drawn from real data and testing conducted by Tennis Lab — led by Dr. Lyon Krause, PhD in Sports Science and one of the world’s foremost experts in tennis equipment.

Tennis Lab operates in partnership with Tennis Australia and provides elite custom racket setups and stringing services at the Australian Open and major pro tournaments. Their facility includes the only public-access Hawk-Eye-equipped court in the world, allowing precise measurement of speed, spin, launch angle, depth, and consistency.

This isn’t theory.

It’s lab-tested data.

Step 1: Understanding the Three Main Types of Tennis Strings

Before choosing tension, you must understand string type.

1. Polyester (Monofilament)

Used by 85–90% of professional players.

Characteristics:

• Stiff

• Low-powered

• Extremely durable

• Excellent control

• High spin potential

Best for:

• Performance players

• Big hitters

• Players who break strings often

Poly gives control through reduced trampoline effect — not extra spin magic.

→ Learn more in: The Best String Types for You (CoachLife)

2. Multifilament

Made of hundreds of woven synthetic fibers.

Characteristics:

• Soft

• Arm-friendly

• Comfortable

• Lower durability

• More power than poly

Best for:

• Recreational players

• Players with elbow pain

• Those who rarely break strings

If you rarely snap strings and still use polyester, you’re likely sacrificing comfort unnecessarily.

3. Natural Gut

Made from cow intestine.

Characteristics:

• Most powerful

• Excellent tension maintenance

• Outstanding feel

• Sensitive to humidity

• Expensive

Natural gut offers elite-level feel and power — but comes with cost and moisture limitations.

Step 2: What String Tension Actually Does (And What It Doesn’t)

Here’s one of the biggest misconceptions in tennis:

High tension = more control
Low tension = more power

That’s not entirely true.

Data from Tennis Lab testing shows:

• Ball speed changes only 1–2% between high and low tensions

• Spin changes minimally

• The primary difference is trajectory

Lower tension:

• Ball sinks deeper into string bed

• Launch angle increases

• Ball travels farther

Higher tension:

• Flatter launch

• Lower trajectory

• Ball lands shorter

In one test comparing 44 lbs vs 54 lbs:

• The ball traveled roughly 0.5 meters farther at 44 lbs

• Speed and spin were nearly identical

• Only the launch angle changed meaningfully

That’s a massive insight.

Tension is about trajectory and depth control — not raw power.

→ Full breakdown: String Tension Explained (CoachLife)

Machine Tension vs Playing Tension

Another critical point:

What you string at is NOT what you play at.

Strings lose approximately 20% of tension shortly after stringing.

Example:

• 56 lbs on the machine

• Drops to 46–48 lbs after a few hours of play

Lower tensions degrade less.

Meaning:

If you string lower, your actual playing tension remains closer to your intended feel.

This is why tension should be adjusted based on landing depth — not machine number.

How Surface and Weather Affect String Tension

Elite players adjust tension constantly.

Faster Surfaces (Grass, Fast Hard Courts)

Players increase tension by 2–4 lbs for added control.

Slower Surfaces (Clay)

Players decrease tension for more launch and depth.

Hot, Dry Conditions

• Ball moves faster

• Players increase tension

Cool, Humid Conditions

• Ball becomes heavier

• Players lower tension for projection

At the Australian Open, average pro tension shifts 2–4 lbs depending on daily weather conditions.

Many players carry rackets strung at different tensions and switch mid-match.

→ See: Trends in String Tension Based on Surface and Weather (CoachLife)

String Tension Is About Style — Not Gender

Data across 32 pro tournaments in Australia shows:

Female players string 4–6 lbs tighter on average than males.

But this is not about gender.

It’s about ball shape.

Men generally:

• Hit heavier topspin

• Use lower tension for lift

Women often:

• Hit flatter

• Use tighter tension to control lower trajectory

If you hit flat — string tighter.

If you hit heavy topspin — string looser.

→ See full breakdown: String Tension Based on Playing Style (CoachLife)

What You Can Learn From Ash Barty and Aryna Sabalenka

Ash Barty played with mid-40 lb tension.

Sabalenka uses mid-to-high 50s.

That’s a 10 lb difference.

Why?

Barty:

• Touch

• Slice

• Variety

• Feel

Sabalenka:

• Raw power

• Early aggression

• Flat hitting

• Requires tighter trajectory control

Tension should amplify your strengths — not fight them.

→ See: What You Can Learn From Barty and Sabalenka’s String Tension (CoachLife)

The Biggest Myths About Tennis Strings

Myth 1: Shaped Strings Automatically Create More Spin

Spin comes from string snapback.

Snapback requires strings to slide freely.

Shaped strings often lock in place, reducing movement and limiting spin.

Myth 2: High Tension = Control

Control comes from trajectory consistency, not stiffness.

Myth 3: String Color Doesn’t Matter

Even identical models in different colors perform differently.

Pigment affects stiffness and tension retention.

• Dark strings = slightly stiffer

• Light strings = livelier feel

→ See: Common Misconceptions About Tennis Strings (CoachLife)

How to Choose the Right String Setup for You

Start here:

1. Choose string type (poly, multi, gut)

2. Choose gauge (1.25mm is standard for performance players)

3. Then fine-tune tension

Recommended baseline starting point:
~48 lbs for calibration.

If balls fly long → Increase tension
If balls land short or into net → Decrease tension

Adjust by:

• 2 lbs for advanced players

• 4 lbs for recreational players

Tension is about feel and landing depth — not ego.

Why Strings Matter More Than Your Racket

Your racket frame matters.

But strings:

• Directly contact the ball

• Dictate launch angle

• Control dwell time

• Influence injury risk

• Shape spin patterns

They are the tires of your game.

Ignoring them limits your ceiling.

Learn From Pro-Level Data Inside CoachLife

All the data referenced here comes from Tennis Lab — the world leader in tennis equipment analytics, led by Dr. Lyon Krause.

Their Hawk-Eye-equipped testing court in Melbourne allows measurement of:

• Ball speed

• Spin rate

• Launch angle

• Landing depth

• Accuracy variance

Insights that were once only available to elite professionals are now accessible to serious players through the CoachLife Tennis Customization & Strings category.

If you want to understand your equipment the way tour players do — start there.

Precision in your setup creates precision in your performance.

Peter Clarke
CoachLife Founder and Former Professional Player
Head Coach at the CoachLife Academy