Head to head

Babolat Synthetic Gut 17 (1.25) vs Gamma Synthetic Gut 18 (1.18)

They split the measurements 3–3. The widest gap is string friction, where Synthetic Gut 17 (1.25) is 24 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.

Measured, side by side

Babolat

Synthetic Gut 17 (1.25)

Nylon · 17 ga

Gamma

Synthetic Gut 18 (1.18)

Nylon · 18 ga

Stiffness lower = softer, kinder on the arm
16229th pct
16532nd pct
Tension loss lower = stays where you strung it
179th pct
155th pct
Energy return higher = livelier, more free power
9276th pct
9381st pct
Spin potential higher = more spin off the string bed
6.079th pct
5.671st pct
Ball bite higher = grabs the ball harder
0.42239th pct
0.46362nd pct
String friction lower = strings slide and snap back
0.0705th pct
0.08229th pct

Bars are percentile against all 791 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 Synthetic Gut 17 (1.25) at 52 lb

String Synthetic Gut 18 (1.18) at 51.3 lb 23.3 kg

Coming from Synthetic Gut 18 (1.18) at 52 lb

String Synthetic Gut 17 (1.25) at 52.7 lb 23.9 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.

Synthetic Gut 17 (1.25) mains / Synthetic Gut 18 (1.18) crosses

Stiffness30th pct · 1 measured
Tension loss8th pct · 1 measured
Energy return80th pct · 1 measured
Spin potential79th pct · 1 measured
Ball bite43rd pct · 1 measured
String friction10th pct · 1 measured

Synthetic Gut 18 (1.18) mains / Synthetic Gut 17 (1.25) crosses

Stiffness31st pct · 1 measured
Tension loss7th pct · 1 measured
Energy return80th pct · 1 measured
Spin potential72nd pct · 1 measured
Ball bite60th pct · 1 measured
String friction21st 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.

Synthetic Gut 17 (1.25)

~37 hours of play

Synthetic Gut 18 (1.18)

~38 hours of play

Both strings in full

Every published measurement
StringGaugePriceStiff lb/inLoss %Power %SpinBite COFFriction COF
Babolat Synthetic Gut 17 (1.25) Nylon17find16217926.00.4220.070
Gamma Synthetic Gut 18 (1.18) Nylon18find16515935.60.4630.082

Add a third string Synthetic Gut 17 (1.25) in full Synthetic Gut 18 (1.18) in full