Head to head

Kirschbaum Pro Line II 17 (1.25) vs Mantis Power Poly 17

Power Poly 17 leads on 4 of 6 measurements. The widest gap is ball bite, where Pro Line II 17 (1.25) is 31 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.

Measured, side by side

Kirschbaum

Pro Line II 17 (1.25)

Polyester · 17 ga

Mantis

Power Poly 17

Polyester · 17 ga

Stiffness lower = softer, kinder on the arm
20169th pct
20471st pct
Tension loss lower = stays where you strung it
4576th pct
4372nd pct
Energy return higher = livelier, more free power
8516th pct
8625th pct
Spin potential higher = more spin off the string bed
4.748th pct
4.851st pct
Ball bite higher = grabs the ball harder
0.47066th pct
0.41735th pct
String friction lower = strings slide and snap back
0.10165th pct
0.08637th 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 Pro Line II 17 (1.25) at 52 lb

String Power Poly 17 at 48.7 lb 22.1 kg

Coming from Power Poly 17 at 52 lb

String Pro Line II 17 (1.25) at 54.5 lb 24.7 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.

Pro Line II 17 (1.25) mains / Power Poly 17 crosses

Stiffness70th pct · 1 measured
Tension loss74th pct · 1 measured
Energy return19th pct · 1 measured
Spin potential49th pct · 1 measured
Ball bite62nd pct · 1 measured
String friction60th pct · 1 measured

Power Poly 17 mains / Pro Line II 17 (1.25) crosses

Stiffness70th pct · 1 measured
Tension loss73rd pct · 1 measured
Energy return22nd pct · 1 measured
Spin potential49th pct · 1 measured
Ball bite41st pct · 1 measured
String friction45th 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.

Pro Line II 17 (1.25)

~17 hours of play

Power Poly 17

~18 hours of play

Both strings in full

Every published measurement
StringGaugePriceStiff lb/inLoss %Power %SpinBite COFFriction COF
Kirschbaum Pro Line II 17 (1.25) Polyester17find20145854.70.4700.101
Mantis Power Poly 17 Polyester17find20443864.80.4170.086

Add a third string Pro Line II 17 (1.25) in full Power Poly 17 in full