Just curious from others' experience. I know tennis is an ageless sport where you see kids up to seniors playing all the time. However, my question is, at what age do you think your game starts to go into decline and you need to adapt your game to your new physical limitations? I'm talking about no longer being able to hit a nasty kicker cause it hurts your back, etc. I'm also not talking about fitness either. I'm taking about when your body can no longer keep up with your former stroke mechanics and you need to change your game, even your equipment. 50s? 60s? I know Johnny Mac is 54 and can still play a pretty good game of tennis. I also know someone who's in his 60's that can still hit a mean kicker (albeit a lot of advil are in order later). Thoughts?