Tension Explained

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Tension is the single cheapest adjustment you can make to how your racquet plays. Same string, same frame — two or three pounds either way changes the feel noticeably. Here is what moves in which direction, and where to start.

Not sure where to start?

Every frame has a manufacturer's recommended range printed on it, usually on the inside of the throat — something like 50–60 lb. That range is your starting point. Where you sit inside it depends mostly on what you put in the racquet:

Co-polyester

Low end
−2 to −4 lb

Poly is stiff to begin with. Most players string it below the middle of the range — and below where they'd string a softer string — to get the feel back. Snake-Bite, Hex Poly, Power Cord.

Synthetic gut

Middle

A solid-core string is happy in the middle of the recommended range. It's the easiest string to judge other tensions against. Synthetic Gut.

Multifilament

Middle to high

These are lively and powerful, so many players go a little tighter to keep the ball in. Velvet, Satin.

Hybrid

Split it

Common practice is to string the stiffer string a couple of pounds lower than the softer one so the two behave more alike. Hybrid guide →

Change one thing at a time. Move in 2 lb steps and play a few sessions before judging. Jumping five pounds and changing string at the same time tells you nothing about which change did what.

What tension actually changes

Read each row left to right: what you gain by going looser, and what you gain by going tighter.

 
Lower tension
Higher tension
Power
More
Less
Control
Less
More
Spin
Less
More
Comfort
More
Less
Durability
More
Less
Dwell time
Longer
Shorter

Gold = the direction that gains. These are tendencies, not guarantees; frame stiffness, string type and how hard you swing all shift the result.

The short version

  • Ball flying long? Go tighter, or switch to a firmer string.
  • Ball falling short, or the racquet feels dead? Go looser — or the string may simply be worn out.
  • Arm or elbow sore? Go looser, and read the note below.
  • Breaking strings too fast? Looser helps a little; a thicker gauge or a co-polyester helps a lot more. Gauges explained →

Why each of those happens

None of this is magic — it all comes from how long the ball stays on the strings and how far the strings move. Open any of these if you want the mechanism.

Why higher tension gives more control

Three things combine. First, a tighter string bed shortens the time the ball is on the strings. Your racquet is rotating through the swing and, on an off-centre hit, twisting — the less time the ball spends in contact, the less the racquet face angle changes while the ball is still on it.

Second, tighter strings move sideways less. That side-to-side movement is why your strings go crooked after a few games, and when a string doesn't return to exactly where it started, the ball leaves at a slightly different angle than you intended. Less movement means more repeatable trajectories.

Third, on a spin shot the ball actually rolls up the string bed during contact. Less dwell time means a shorter roll and a more predictable launch.

Why lower tension gives more power

Strings are far more efficient springs than tennis balls. Strings return roughly 95% of the energy put into them; a ball returns closer to 55% — the rest is lost as heat in the rubber.

A looser string bed deflects more and compresses the ball less, so more of the impact energy is stored in the efficient spring (the strings) and less in the lossy one (the ball). More of it comes back, so the ball leaves faster.

Why higher tension can give more usable spin

This one is counter-intuitive. For an identical swing, the raw spin rate off a tight bed is barely different from a loose one. What changes is the ratio of spin to ball speed: a tighter bed returns less pace for the same swing.

That lower power is what lets you swing harder without hitting long — and swinging harder is what actually creates the spin. So the tighter setup doesn't add spin by itself; it gives you the headroom to go after the ball.

Why lower tension is easier on the arm

A looser bed holds the ball fractionally longer, which spreads the same impulse over more time. Peak force is lower, so the shock travelling back into your wrist and elbow is lower. In plain terms: more cushion.

Why lower tension lasts longer

Two reasons. Where mains and crosses cross each other, a looser bed presses them together with less force, so they saw into each other more slowly. And a string held at lower tension carries less constant internal stress, so it takes longer to fatigue.

Tension doesn't stay where you put it

Every string starts losing tension the moment it comes off the machine — a noticeable drop in the first 24 hours, then a slow decline with every hour you play. That is normal and it is why a string bed can feel dead long before anything breaks.

Co-polyester loses tension fastest, which is why poly players restring on a schedule rather than waiting for a break — roughly every 15 to 25 hours of play. Solid-core and multifilament strings hold tension better and give you more warning, usually going soft and mushy rather than simply dying.

A rough guide: restring as many times per year as you play per week. Twice a week, twice a year. That is a floor, not a ceiling — if you play with poly or you're competitive, restring more often.

If your arm hurts

Tension is one of three levers, and it's the easiest to pull. Dropping a few pounds helps. But if you're playing a full bed of co-polyester and the elbow is complaining, tension alone usually isn't enough — the string is the bigger factor. A softer string in the crosses, or moving to a multifilament, will do more than a couple of pounds ever will.

How hybrids work →

Shop all tennis strings → Compare cost per restring →

Related: Hybrid guide · Gauges explained · String materials & construction

Recommended ranges are a starting point, not a rule — your frame, your swing and your string all move the answer. Updated September 2026.