How strings affect spin
TenisRaketi Editör Ekibi · Updated October 2026
Short answer
Most spin comes from your swing; strings make it easier or harder. On the string side the biggest effect is the mains sliding and snapping back: a slick polyester and an open string pattern increase it. A shaped cross-section has a smaller effect, and it fades as the string wears.
In this guide
Strings sold as "spin strings" are mostly shaped polyesters. But what strings add to spin depends less on how much the surface "grips" the ball and more on how freely the strings move. This guide explains how spin forms on the strings and how much each choice matters.
First: spin comes from the swing
How much spin you put on the ball depends mostly on how fast and how steeply low-to-high you swing. Strings, racket and tension can add or take away a little, but they cannot turn a slow, flat swing into a spinny shot.
The mains slide and snap back
When the ball hits the strings, the racket swinging up drags the ball across the string bed. The ball pushes the mains (the vertical strings) sideways over the crosses. Just before the ball leaves, the mains spring back into place, and that movement adds spin. This is called "snapback".
Lab measurements show that this slide and snapback makes up most of what strings add to spin. It needs two things: strings that slide over each other easily (low friction) and a ball that grips the strings well.
What matters how much?
Factor | Effect on spin | Why |
|---|---|---|
String type | Large | Polyester is slick, so the mains slide and snap back easily. Multifilament and natural gut have more friction. |
String pattern | Large | In an open pattern (16×19, 16×18) the strings are further apart and freer. |
Cross-section shape | Small–medium | A shaped string grips the ball a little better; the effect fades as it wears. |
Tension | Small | At lower tension the ball sinks in more and the strings move more easily. |
Gauge | Small | A thinner string grips a little better and slides more freely. |
For the racket side of spin, see the best rackets for spin list.
Round, shaped, twisted
Cross-section | How it feels | Watch out |
|---|---|---|
Round | Smooth and predictable; the strings slide easily | Spin is left to type and pattern |
Shaped (pentagon, hexagon, octagon) | "Bites" the ball a little more | The edges round off over time; the early effect does not last |
Twisted or textured | Rough surface that grips the ball | The strings can rub each other more |
Shaped strings are not a bad choice, but they are not magic either. A slick round polyester can give as much spin as a rough shaped one, or more.
When the strings stay out of place
If you see the mains slide sideways and stay there after shots, the strings have notched (worn into each other). Notched strings cannot slide and snap back, so spin drops. With polyester this is one of the clearest signs that the string is dead. Even if it has not broken, it is time to restring; more in the when to restring guide.
A short recommendation
- If you want more spin: An open-pattern racket, a round or shaped polyester, and a tension in the middle of the range or a little below.
- If your arm is sensitive: Choose a soft polyester, or a hybrid of polyester mains and soft crosses. Do not strain your arm for spin; see the arm-friendly strings guide.
- If you are new: You do not need a spin string yet. Sort out your swing first; multifilament or synthetic gut is enough.
Frequently asked questions
Which string gives the most spin?
Generally a slick polyester. The strings slide over each other and snap back, which adds spin. A shaped cross-section adds a little. The effect grows on an open-pattern racket.
Do shaped strings really give more spin?
A little. A shaped string grips the ball better, but most of the spin comes from the strings sliding and snapping back. The edges also round off over time, so the effect fades.
Does lower tension increase spin?
Slightly: the ball sinks in more and the strings move more easily. But the effect is small next to string type and pattern.
My mains keep shifting sideways. Is that normal?
The strings slide and spring back on every shot. If they stay out of place and you have to straighten them by hand, they have worn into each other. Spin drops at that point; it is time to restring.
More guides on this topic
- How to choose tennis stringsFor most players multifilament or synthetic gut is a safe starting point. Hard hitters who break strings often go for polyester, and players who put arm health first choose multifilament or natural gut. A gauge of about 1.25 mm is a good balance.
- Tennis string tension: what should it be?Start in the middle of the range printed on your racket: the exact middle for multifilament, synthetic and natural gut, and about 1 kg (2 lb) lower for polyester. Lower tension gives more power and comfort, higher tension gives more control. Change it by no more than 1 kg at a time.
- Types of tennis stringsThere are four main types: natural gut (softest, most expensive), multifilament (soft and powerful), synthetic gut (cheap, all-round) and polyester (stiff, controlled, durable). Aramid is only used in hybrids. How fast you break strings and how sensitive your arm is decide the type.
- How to choose tennis string gauge1.25–1.30 mm is a good balance for most players. Thin strings (1.15–1.20 mm) give more feel and a little more spin but break sooner; thick strings (1.30 mm and up) last longer. Gauge numbers vary between brands, so always go by millimetres.
- How to choose arm-friendly stringsNatural gut and multifilament are the easiest strings on the arm. If you want to use polyester, choose a soft model, a thin gauge and a tension at the low end of the range, and restring before it goes dead. A vibration dampener does not protect your arm.
- When to restring a tennis racketThe practical rule: restring as many times a year as the days you play per week. If you play three days a week, three times a year. With polyester, restring more often; it goes dead within weeks even if it does not break. If the racket feels harsh, balls fly long or the strings stay out of place, it is time.