StringSpec
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Browse all 788

Head to head

Gamma Synthetic Gut 18 (1.18) vs Gosen AK Pro Spin 15L (1.38)

They split the measurements 3–3. The widest gap is string friction, where AK Pro Spin 15L (1.38) is 17 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.

Measured, side by side

Gamma

Synthetic Gut 18 (1.18)

Nylon · 18 ga

Gosen

AK Pro Spin 15L (1.38)

Nylon · 15L ga

Stiffness lower = softer, kinder on the arm
16532nd pct
16937th pct
Tension loss lower = stays where you strung it
155th pct
121st pct
Energy return higher = livelier, more free power
9381st pct
9274th pct
Spin potential higher = more spin off the string bed
5.671st pct
6.079th pct
Ball bite higher = grabs the ball harder
0.46363rd pct
0.44653rd pct
String friction lower = strings slide and snap back
0.08228th pct
0.07411th 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 Synthetic Gut 18 (1.18) at 52 lb

String AK Pro Spin 15L (1.38) at 50.8 lb 23.0 kg

Coming from AK Pro Spin 15L (1.38) at 52 lb

String Synthetic Gut 18 (1.18) at 53.3 lb 24.2 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 18 (1.18) mains / AK Pro Spin 15L (1.38) crosses

Stiffness34th pct · 1 measured
Tension loss3rd pct · 1 measured
Energy return78th pct · 1 measured
Spin potential73rd pct · 1 measured
Ball bite61st pct · 1 measured
String friction23rd pct · 1 measured

AK Pro Spin 15L (1.38) mains / Synthetic Gut 18 (1.18) crosses

Stiffness35th pct · 1 measured
Tension loss1st pct · 1 measured
Energy return76th pct · 1 measured
Spin potential79th pct · 1 measured
Ball bite55th pct · 1 measured
String friction15th 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 18 (1.18)

~38 hours of play

AK Pro Spin 15L (1.38)

~40 hours of play

Both strings in full

Every published measurement
StringGaugePriceStiff lb/inLoss %Power %SpinBite COFFriction COF
Gamma Synthetic Gut 18 (1.18) Nylon18find16515935.60.4630.082
Gosen AK Pro Spin 15L (1.38) Nylon15Lfind16912926.00.4460.074

Add a third string Synthetic Gut 18 (1.18) in full AK Pro Spin 15L (1.38) in full