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Browse all 791

Head to head

Gamma IO Soft 17 (1.23) vs Yonex Poly Tour Fire 16L (1.25)

IO Soft 17 (1.23) leads on 5 of 6 measurements. The widest gap is energy return, where IO Soft 17 (1.23) is 7 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.

Measured, side by side

Gamma

IO Soft 17 (1.23)

Polyester · 17 ga

Yonex

Poly Tour Fire 16L (1.25)

Polyester · 16L ga

Stiffness lower = softer, kinder on the arm
19360th pct
19563rd pct
Tension loss lower = stays where you strung it
3456th pct
3558th pct
Energy return higher = livelier, more free power
8739th pct
8733rd pct
Spin potential higher = more spin off the string bed
5.978th pct
5.876th pct
Ball bite higher = grabs the ball harder
0.44050th pct
0.44351st pct
String friction lower = strings slide and snap back
0.07514th pct
0.07615th 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 IO Soft 17 (1.23) at 52 lb

String Poly Tour Fire 16L (1.25) at 51.4 lb 23.3 kg

Coming from Poly Tour Fire 16L (1.25) at 52 lb

String IO Soft 17 (1.23) at 52.6 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.

IO Soft 17 (1.23) mains / Poly Tour Fire 16L (1.25) crosses

Stiffness61st pct · 1 measured
Tension loss56th pct · 1 measured
Energy return36th pct · 1 measured
Spin potential77th pct · 1 measured
Ball bite50th pct · 1 measured
String friction14th pct · 1 measured

Poly Tour Fire 16L (1.25) mains / IO Soft 17 (1.23) crosses

Stiffness61st pct · 1 measured
Tension loss57th pct · 1 measured
Energy return35th pct · 1 measured
Spin potential77th pct · 1 measured
Ball bite51st pct · 1 measured
String friction14th 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 17 (1.23)

~23 hours of play

Poly Tour Fire 16L (1.25)

~22 hours of play

Both strings in full

Every published measurement
StringGaugePriceStiff lb/inLoss %Power %SpinBite COFFriction COF
Gamma IO Soft 17 (1.23) Polyester17find19334875.90.4400.075
Yonex Poly Tour Fire 16L (1.25) Polyester16Lfind19535875.80.4430.076

Add a third string IO Soft 17 (1.23) in full Poly Tour Fire 16L (1.25) in full