Kirschbaum Pro Line I 18L (1.15) vs MSV Co.-Focus 16L

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.

• More spin and shape

  Pro Line I 18L (1.15)461st

  Co.-Focus 16L490th

• Easier on my arm

  Pro Line I 18L (1.15)535th

  Co.-Focus 16L473rd

• More control, less launch

  Pro Line I 18L (1.15)310th

  Co.-Focus 16L401st

• More power and depth

  Pro Line I 18L (1.15)619th

  Co.-Focus 16L528th

• Plays the same for longer

  Pro Line I 18L (1.15)695th

  Co.-Focus 16L681st

• Lasts longer before it breaks

  Pro Line I 18L (1.15)417th

  Co.-Focus 16L278th

• Best feel and touch

  Pro Line I 18L (1.15)638th

  Co.-Focus 16L554th

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 Pro Line I 18L (1.15) in full Co.-Focus 16L in full