Head to head
Gamma IO Soft 17 (1.23) vs Tourna Black Zone 17
Black Zone 17 leads on 5 of 6 measurements. The widest gap is ball bite, where Black Zone 17 is 19 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.
Measured, side by side
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.
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IO Soft 17 (1.23)173rd
Black Zone 17147th
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IO Soft 17 (1.23)415th
Black Zone 17353rd
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IO Soft 17 (1.23)325th
Black Zone 17410th
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IO Soft 17 (1.23)418th
Black Zone 17345th
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IO Soft 17 (1.23)444th
Black Zone 17408th
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IO Soft 17 (1.23)23rd
Black Zone 1751st
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IO Soft 17 (1.23)414th
Black Zone 17338th
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 Black Zone 17 at 53.6 lb 24.3 kg
Coming from Black Zone 17 at 52 lb
String IO Soft 17 (1.23) at 50.5 lb 22.9 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 / Black Zone 17 crosses
Black Zone 17 mains / IO Soft 17 (1.23) crosses
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
Black Zone 17
~25 hours of play
Both strings in full
| String | Gauge | Price | Stiff lb/in | Loss % | Power % | Spin | Bite COF | Friction COF |
|---|---|---|---|---|---|---|---|---|
| Gamma IO Soft 17 (1.23) Polyester | 17 | find | 193 | 34 | 87 | 5.9 | 0.440 | 0.075 |
| Tourna Black Zone 17 Polyester | 17 | find | 187 | 32 | 88 | 6.0 | 0.477 | 0.080 |
Add a third string IO Soft 17 (1.23) in full Black Zone 17 in full