Does 15% Tension Loss Mean a String Is Bad?
A 15% loss figure is not a report card for a string. It summarizes how that stringbed changed relative to a chosen baseline under one consistent measurement procedure.
Start with this check
Strings relax during stringing and immediately afterward, with relatively rapid change often occurring in the first hours and first play. The calculated loss depends on the chosen baseline: a percentage using machine-set reference tension as the denominator is not the same metric as one using a post-stringing app baseline. An app estimates current average tension; it does not directly read the original machine setting or summarize every aspect of stringbed-stiffness change. Do not rank 15% figures from two racquets as though they measured quality when material, gauge, temperature, playing impact, and measurement procedure differ.
Try these steps in order
- Set the baseline to a repeatable point in time, such as “the day after stringing, before play, in the same room,” and save the median of three measurements as the baseline.
- Take later readings with the same app version, input values, support method, and excitation point. Do not silently delete readings affected by noise or an abnormal tap; label them as outliers.
- Use only the baseline and current estimate for the loss rate calculation, and preserve the stringing machine's reference tension as a separate process value. Specify which denominator was used on the screen and in the records.
- Record cumulative playing time, session count, storage temperature, balls, court, and rain exposure so elapsed-time effects can be distinguished from use-related impact.
- Alongside the numbers, check whether the mains return to position, whether intersection notches deepen, and whether launch-angle consistency, depth consistency, or arm comfort changes.
- Create a personal warning zone only after several restringing cycles show a similar curve for the same product. Do not present that personal range as a universal threshold.
Bottom line
Tension-loss percentage is a trend measured under consistent conditions. Combine it with playing time, wear, snapback, and on-court response when deciding when to restring.
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Reviewed sources
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