why has fed's strokes changed over the years?

[rosewall4ever]

Never have i seen a player changed so much throughout over the years, which is evident from youtube videos pre 2006. Granted he had to adjust his bh due to height of spin from players, but his forehand that was more linear back then has gone backwards in its effectivness. His attacking approach does not suit the spiny shots he has now, which we all know gets crushed by other players...IMO

thoughts??? is it more/less about strokes, or more about the age factor, or superior players than the fed dominance years

 

[PCXL-Fan]

I noticed after his bout with mono, he seemed to have less pop in his strokes.