Originally Posted by The tennis guy
It has more to do with other players improving than Federer's decline. Now players can put him in defensive position without giving up that advantage during a rally. The key to Federer today is he has to be more aggressive than he used to, in return, he will be less consistent. Federer has to accept this trade off, and be more aggressive than he used to.
+1 for some reason, people never want to give credit to the other player. Federer has a losing record against Djokovic this year. Does that mean Federer is declining - no, it means Djokovic has improved, hence his record season.