^ With all due respect, but this is just gibberish.
There is absolutely no objective 'need' for Federer to win this. 17 or 18; who gives a crap. The guy is in the lead by a pretty wide margin. This might be his last chance, but he has had plenty of chances before.
Djokovic, on the other hand, is still chasing people and is on the verge of breaking double digits. Besides, Djokovic needs to imporve his final record here at the US Open.
oh and the fact that you say you don't think Djokovic will reach 17 proves my point. Djokovic needs it badly.