StringSpec
String finder

Browse all 788

Head to head

Gamma IO Soft 15L (1.40) vs L-Tec Premium 4S 16L (1.25)

IO Soft 15L (1.40) leads on 4 of 6 measurements. The widest gap is ball bite, where Premium 4S 16L (1.25) is 34 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.

Measured, side by side

Gamma

IO Soft 15L (1.40)

Polyester · 15L ga

L-Tec

Premium 4S 16L (1.25)

Polyester · 16L ga

Stiffness lower = softer, kinder on the arm
22087th pct
23495th pct
Tension loss lower = stays where you strung it
3354th pct
3559th pct
Energy return higher = livelier, more free power
8846th pct
8739th pct
Spin potential higher = more spin off the string bed
6.384th pct
6.788th pct
Ball bite higher = grabs the ball harder
0.41836th pct
0.47970th pct
String friction lower = strings slide and snap back
0.0662nd pct
0.0716th pct

Bars are percentile against all 788 strings, and the marked side is the one that measures better, which is not always the one you want. A firmer bed is worse for your elbow and better for your control, and no measurement knows which of those you came for.

Which one wins, by problem

Each string's standing on the site's rankings, out of every measured string in the database. This is where a comparison stops being arithmetic and starts being a decision.

Swapping between them: what tension?

Bed stiffness is published at one reference tension, so the only honest conversion is to scale it. These are starting points from 52 lb, not prescriptions. The calculator takes your own tension.

Coming from IO Soft 15L (1.40) at 52 lb

String Premium 4S 16L (1.25) at 48.8 lb 22.1 kg

Coming from Premium 4S 16L (1.25) at 52 lb

String IO Soft 15L (1.40) at 55.4 lb 25.1 kg

Hybrid: what if you used both?

Estimated, not measured. No hybrid combination has been tested as a bed. These figures are the two strings' own lab measurements weighted by how much of the bed each one actually is. Treat them as a guide to which way a pairing moves, never as lab data.

IO Soft 15L (1.40) mains / Premium 4S 16L (1.25) crosses

Stiffness91st pct · 1 measured
Tension loss56th pct · 1 measured
Energy return43rd pct · 1 measured
Spin potential84th pct · 1 measured
Ball bite42nd pct · 1 measured
String friction2nd pct · 1 measured

Premium 4S 16L (1.25) mains / IO Soft 15L (1.40) crosses

Stiffness93rd pct · 1 measured
Tension loss57th pct · 1 measured
Energy return42nd pct · 1 measured
Spin potential88th pct · 1 measured
Ball bite66th pct · 1 measured
String friction4th pct · 1 measured

Open this in the hybrid builder

Which goes dead first?

Estimated from tension loss, which is the only thing the database measures about ageing. This is when the bed stops playing the way you strung it, not when the string breaks.

IO Soft 15L (1.40)

~24 hours of play

Premium 4S 16L (1.25)

~22 hours of play

Both strings in full

Every published measurement
StringGaugePriceStiff lb/inLoss %Power %SpinBite COFFriction COF
Gamma IO Soft 15L (1.40) Polyester15Lfind22033886.30.4180.066
L-Tec Premium 4S 16L (1.25) Polyester16Lfind23435876.70.4790.071

Add a third string IO Soft 15L (1.40) in full Premium 4S 16L (1.25) in full