I just saw this article at tennis.com:
http://www.tennis.com/pro-game/2014/04/when-rafa-blinked/51299/#.U1-42WdOWpo
This is a great article. I agree on so many fronts.
1. The point of diminishing returns, and
2. Champions fatigue
I'm just surprised that it took so long. Everyone gets tired, even if you're at the top of the game.
This is what I thought when Federer went through his slump. People were writing him off, but I didn't see any decrease in skills. Just mental fatigue.
These two have battled at the highest level for ten years. That's ridiculously consistent.
Bodo actually got it right, this time.