Audrey, pg. 10 of Bernhard’s article should be of interest to you…
“If the load of a string is near up to breaking limit, the
string will be continous elongatied by the constant
overload so it has to be compensated by tuning
again. During the time the string gets more and
more thinner and weaker until it breaks. This can
also happen after one year or later. One shouldn‘t
forget that the stress on the string is not spreaded
equal because of the friction at the bridge pins. The
bigger the bend is on the bridge pin the bigger is the
friction, and the bigger must be the reserver on the
wire.”
It all makes sense.