@engineer,
Aha! makes sense he doesn't just fade but is dealing with issues.
I was never a serious tennis player, who me?, but I did like playing in beginning uni tennis class, and with friends who were good who put up we me later. One a junior champion from her country; she was patient with us, in retrospect.
Before that, I remember being consternated on where to move to in doubles on a date with a good t.player (also + math physics music, wonder if there is a connection).
But one day in those beginner classes I didn't have my racquet (forget why) and a fellow student leant me hers; this was back in the days of woods. I forget the brand name now, but with her racquet, I became queen of the court and could do no wrong. Back with my own racquet next time, nah. Years later I tried one of those racquets again, and, eh..
Maybe it had to do with how that player maintained her racquet - I've no idea.
Hah, I remember the name, Slazenger.