Originally Posted by DekuTheEvilClown
The players who've lasted the longest i.e. connors, lendl and Agassi all had heavy baseline games. Connors was a full on grinder.
Whereas people like Edberg and Macenroe who played a physically less intensive smoother game never had late success.
For me this kills the theory of physical burnout. It's more about the mental side, in regards to how long a player can last at the top.
For Borg it was mental burnout as he had been playing professionally since his late teen years, 17 or 18, until he was 26 or so.
Wilander retired relatively early because his style, solid baseline play combined with opportune sorties to the net, required a mental and physical exertion that was unsustainable.
Agassi's career went as long as it did because he had numerous stretches when he was indifferent to the sport. If you recall he even dropped out of the top 100 when he was good enuff to be in the top 3.
As to Connors, initially he was not a grinder, but a big hitter who could end points quickly from the baseline. He adapted to become a scrambler and grinder because it was the only way to compete against big servers like McEnroe and big topspin forehand hitters like Llendl.
I think Federer will retire the day the big serve, big forehand style of play becomes obsolete or when age catches up to him to the extent his loss of agility will cost him dearly, more likely the latter than the former which I foresee to be 5 to 7 years from now.