I used to gig 5 hrs a night, 4 nights a week in some pretty gnarly, smoky, sweaty conditions. I changed strings once per month. I bought in bulk to help defray some of the cost. That was years ago and now I change my strings maybe 3 times a year on my most used basses and 1 time a year on the lesser ones. I usually use nickel rounds. So my question is, I've got some strings left over from the old days that have always been stored in their original packaging without exposure to any extremes. BUT they are getting on in age. One of my twelve packs of Ernie Ball Slinkys has got to be getting on towards 8 or 9 years old. Should I hurry up and use them for the sake of using them? Will they be okay to use as necessity dictates? Will their useful lifespan be shorter? I've got maybe 25 sets of strings to get through that range from that old box at 9 years up to a few sets that are maybe 4 years young. The newer ones were usually freebies or whatever as clearly I don't need to go out and buy strings. So whach'all think?