For me, I just look at the over all condition of the stitching and seams, and feel how sturdy the shell is. My last pair of skates, the toe cap was beginning come loose from the rest of the boot and the shell was softening up, but I stretched the life of the skate out a couple of years. Skate was around 7 years old by the time I replaced it. Right now, my skates are around 5 years old. Other than surface abrasions, it looks like it should easily last another 2 years. They're S190s. I'm usually on the ice 3-4 times a week. Usually it's 2-3 games and/or 1-2 sessions of stick and puck.