Federer looks good to possibly be Australian Open runner up this year. Not bad for a 31-year-old. Eventually, there will come a time, if Roger keeps playing, when he'll fail to reach the quarters of a major. That hasn't happened since 2004, but no one would be surprised to see it happening within the next 18-24 months. The big question I guess is whether he'll retire before that happens, or how long he keeps playing after that happens. His natural elegance of movement has helped keep Federer injury-free all these years, and it may well prolong his career. I don't see him quitting as long as he has a shot at grand slam finals. Nadal hasn't been so fortunate. Even though Nadal became one of the all-round greats when he was able to adapt his unique playing style to hard court tennis, the effort took a heavy toll on his knees. The rest of Nadal's career is going to be about preserving his joints so he can stretch his Roland Garros record to something no one will be able to match for decades. At least, that's how I hope it plays out.