First, to appease the readers who will flood the comments with Greatest of All Time arguments: Roger Federer is the greatest ever on the men's side, and he will be for a long time. Don't expect Nadal to match his grand slam total, even though he'll get close, and let's not even bring Djokovic into the conversation.
Federer has made it look so easy that his accomplishments are still under-appreciated. That streak of 23 consecutive semifinals will remain among the hardest records to break in all of sport. His fluid movement and easy power at times made his march through the history books look deceptively casual.
But Federer is 30. He could hang around the top four another couple seasons, and around the top 10 until he's 35 if he wanted to. But in tennis years, Federer is past his prime.
The season he's had, except for a stellar French Open, has been sub-par and has featured some surprising losses to players he once owned on stages he once ruled. The drought since the 2010 Australian Open has included only one final, at Roland Garros, and three quarterfinal exits.
This year will mark the first year that he doesn't win a slam. Here is why that storyline will continue in the coming seasons, broken down by slam:
If Federer wins another slam, where will it be?
On the most democratic surface in tennis, Federer found a way to dominate. Winning five in a row at Wimbledon was remarkable, but we'd seen it before; winning five in a row at Flushing Meadows was mind-blowing and unprecedented. Federer is one of the best schedule managers ever, and he always had plenty left in the tank for New York. Where hard courts beat up the other players, Federer seemed to float above them.
But Federer is a step slower now, and that's a big problem. It now means that he's playing defense more often, and it means that he can be hit off the court. The 2009 final against Del Potro and 2010 semifinal against Djokovic were close affairs but featured too many big moments that Federer lost from being overpowered. On a given day on hard courts, Roger could still take down Murray, Nadal and even the new Djokovic, but he likely can't do it in consecutive matches.
Likely result: Finals this year, quarterfinals in 2012.
The analysis is similar here to the US Open. The surface in Melbourne is faster than it used to be but is still a slower-paced hard court. The slightly slower courts will help Federer get to more balls, and the bounce is still not too high on most balls from Nadal to hurt Federer's one-handed backhand consistently.
The timing of Australia is also good for Federer. He's never had an issue with heat, and he seems to be one of the few players who comes into January in peak form. Federer should continue to do well there as long as he plays the tournament. However, Djokovic and Murray have also proved to be very strong on the plexicushion courts. Whichever one doesn't win the US Open will come into Melbourne well rested and hungry to either get back to winning (Djokovic) or finally break through (Murray).
Likely result: Semifinals in 2012. If he plays 2013, semifinals.
Here's a shock prediction: If Federer wins one more slam, it will be in Paris. Obviously, this is Federer's worst slam, but many forget that he's still the second best clay court player of his era. He's made four finals and a semifinal and won it once with an assist from Soderling. His movement on clay is great, and the ability to slide should help make up some of the difference in raw foot speed he's losing to other players now. Plus, the big hitters will be less threatening on that surface.
But that's a big "if" that requires Nadal to have an off year at the French Open in either 2012 or 2013. True, in the quarterfinals and earlier, Rafa is not always as sharp or as patient as he needs to be. However, he will probably be guarding clay even more enviously now that Djokovic is a real rival. While Roger could sneak through if the field opened up, I don't see him getting past an in-form Nole or Rafa.
Likely result: Finals in 2012. If he plays 2013, quarterfinals.
Many of the commentators used to talk about grass as Federer's best surface, and believed he could win at SW19 well into his 30s. But Wimbledon has started to play more like hard courts in recent years, with higher bounces and slower speed allowing Nadal and the other baseliners to gain an edge. In the second week, much of the court barely has grass.
Without the advantage of a Sampras-like serve, much less a willingness to play an aggressive serve-volley style, Federer was never likely to keep racking up the Wimbledon titles once the courts slowed down. Losses to Tsonga this year and Berdych last year in the quarterfinals are troubling.
Wimbledon could very well be the grand slam where Federer's quarterfinals streak finally ends.
Likely result: Fourth round in 2012, silver medal at the Olympics held there next year. If he plays 2013, quarterfinals.