<blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;" class="gmail_quote"><div> ...I would like to give an unscientific, but real world account...</div></blockquote><div>Anecdotal  evadance, though conindered "weak" by scientific standards, can still valuable if accurate. More importantly, anecdotal evadance is powerful in the human mind. We have a tendency to privately judge the trustworthiness of scientific explanations and models by how well those models explain things that happen to us personally. A primary weakness to anecdotal evidence it that it tends to grant unwarranted significance to anomalies. I am no expert in piano wire physics, but my initial guess ifs that the Petrov must have either gotten more than the usual number of tunings before it was shipped and/or (more likely) it had been sitting in warehouses and store floors for a year or years before it was sold "new". (Do Petrov's fly off the shelf?) Maybe it got most of it's stretch out before you encountered it? Any other ideas? [k] </div>