Polyester, multifilament, hybrids, natural gut. Each string tested for at least 20 hours across reference frames at three tensions, scored on eight metrics.
You have probably asked it after a string job felt suddenly alive: did the new setup actually give me more power, or am I just swinging looser because the racquet feels better?
For a string that costs three to four times what a quality polyester does, natural gut tennis strings carry a stubborn reputation: relics for purists, priced for people who don't read the spec sheet.
The advice you hear in every pro shop and every elbow-pain forum thread is simple: if your arm is hurting, switch to natural gut.
A string design patented in the 1870s has no business outperforming a polyester engineered with last decade's polymer science.