I have read from many posters here that a poly string job like PHT or Lux will last about 20 hrs before it goes dead. And I used to play with only one racket, and just restring after they broke. However, I went and bought a proper set of two rackets now, and it got me to thinking about the shelf life of backup rackets. If I string up a backup racket with a full set of poly - and DO NOT play with it for like a month or two - will the tension and playability of the string be degraded to a significant degree? How do you guys manage your second or third rackets string jobs when you knowthey may sit for months on end? ie, I have my third racket, which now I am thinking may sit in the bag for 6 months or longer before I may use it as a backup racket in an emergency. What would be the best long-term string that would not lose all of it's playability sitting in a bag that long?