Kirschbaum Long Life 15 vs Kirschbaum Pro Line I 1.30

Measured, side by side

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.

• More spin and shape

  Long Life 15396th

  Pro Line I 1.30455th

• Easier on my arm

  Long Life 15784th

  Pro Line I 1.30776th

• More control, less launch

  Long Life 152nd

  Pro Line I 1.3028th

• More power and depth

  Long Life 15784th

  Pro Line I 1.30765th

• Plays the same for longer

  Long Life 15744th

  Pro Line I 1.30660th

• Lasts longer before it breaks

  Long Life 1594th

  Pro Line I 1.3090th

• Best feel and touch

  Long Life 15784th

  Pro Line I 1.30769th

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.

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.

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.

Both strings in full

Add a third string Long Life 15 in full Pro Line I 1.30 in full