The main cause of strings breaking is excessive spin. If you
play with lots of spin, you cause the strings to slide. Under the tensions these
strings are under, this causes notches which you can actually see. The notches eventually
break. The harder you hit, and the more spin you hit, the more likely the strings
will break sooner.
One way to avoid this problem (or at least prolong string life) is
to use inserts called "String-a-lings" that prevent the strings from sliding too
much.
String Savers (the Prince version of string-a-lings) are little
plastic pieces that are inserted where the strings touch around the sweetspot of the
racquet. They prevent your strings from rubbing against each other, and are intended to
help prolong string life. String Savers are legal because the ball never actually touches
them.
String Savers are mostly used by players that have gut strings. They
are usually effective at prolonging string life - but how much will vary.
Some players complain that they fall out, particularly if they hit
with a lot of spin. Some players also do not like String Savers because the give the
racquet a stiffer feel. Another alternative to lengthen string life is to use a
thicker guage string or to string at a higher tension . Higher tensions means less
string sliding but can mean a greater likelihood that a string will snap (because of
higher tensile pressure).
There is a little picture on the String Savers box showing how to
install them, along with a tool for insertion. One box includes enough for one racquet.
