When the year 2012 began, nobody believed Roger Federer would win another Grand Slam, considering he had just gone a full year (2011) without winning any majors. Yes, he had won a few tournaments, specially toward the end of the year. But we all know, at Federer's level, its the majors that matter to him.
For him to win Wimbledon convincingly, beating Djokovic and Murray, and then get the Olympic silver medal (yes, he lost to Murray easily), and now for him to be the favorite at the U.S. Open is a remarkable turnaround, even for a guy named Federer.
You wonder what was responsible for this turnaround. We can find reasons like Nadal's demise with or without injury, Djokovic's sudden loss of form this summer, etc. etc. But to me, the real reason behind Federer's climb back to the top is the backhand.
In those crucial matches, Federer's backhand kept him in those rallies that he would have otherwise lost. And there were times when his backhand was a weapon and he was able to employ it by crushing winners down the line with his backhand, something unimaginable once in his career.
Both Djokovic and Nadal—especially Nadal—have exploited Federer's weak backhand in the past. Nadal famously used to hit topspin high to Federer's backhand and obtain a weak response, thus being able to gain advantage in the rally before going for the winner. Djokovic used to hit his angles better than anyone, hitting all corners of the court and getting neutral balls from the Federer backhand that Djokovic was able to exploit with his court coverage.
However, with Federer's improved backhand, those shots are no longer feeble, and some of them are actually coming back with interest.
Federer improving his backhand comes from years of hard work with Paul Annacone, his coach, and has certainly paid dividends at this stage of his career. Whether he will win multiple more majors going forward, I do not know. But there is no question that Federer has made life even more difficult for his opponents.
Not only has this made his opponents think more about this backhand and now respect that shot, this has gotten them thinking overall and created that little bit of doubt.
Before, Djokovic or Nadal would feel confident that they were the favorites to win against Federer. Now, they would feel it's 50-50, or even slightly in favor of Federer.
I would not be surprised if and when Nadal returns and is back to his best, and he plays Federer at this level, that their matches would be that much more competitive, but a Nadal win cannot be a guaranteed result anymore.
With Djokovic, he needs to tighten his game even more and strengthen himself mentally, because that is an aspect of his game that is still suspect. Against the best, there is no room for self-doubt, and in his current form, it has to be said—Federer is the very best!