There is a tremendous lack of parity on the men's tour at the moment, best highlighted by the results of the most recent four Grand Slams, including the soon to be completed 2012 Australian Open.
That one player was Jo-Wilfried Tsonga who made the Wimbledon semifinals last year by defeating Federer in the quarters.
Aside from that one loss by Fed, the Big Four in men's tennis have only been beaten by one another in Grand Slam competition in the last four majors. That is a trend that will continue in Melbourne Park as the Big Four have dominated the tournament this season, often winning their matches without much doubt.
In fact, against the rest of the field in the last year, Djokovic, Nadal, Federer, and Murray are a crushing 79-1 in Grand Slam singles matches prior to the semifinal round (including walkovers and wins via retirements as victories).
When you include Djokovic's defeat of Tsonga in the Wimbledon semis, that record improves slightly to 80-1 when the Big Four plays against any non-Big Four player in a major.
A degree of dominance by the high seeds is definitely to be expected in Grand Slams. However, just how dominant Djokovic, Nadal, Federer, and Murray have been in the last four majors is still surprising.
Typically Grand Slams have major upsets in the early or middle rounds, like in 2010 when Stanislas Wawrinka eliminated Murray from the US Open.
Earlier that year we saw Tomas Berdych eliminate Federer in the Wimbledon quarterfinals.
At the 2010 French Open we saw both Federer and Djokovic suffer quarterfinal round upsets as Robin Soderling and Jurgen Melzer advanced, respectively.
Back in 2009 there were several upsets to the top four players in Slams. Second-seeded Murray lost to Marin Cilic in the US Open fourth round, 24th seeded Tommy Haas eliminated 4th seeded Novak Djokovic in the Wimbledon quarters, and Robin Soderling pulled off the biggest shocker in eliminating Rafael Nadal in the fourth round at Roland Garros.
The dominance of the Big Four in Grand Slam play is quite remarkable. However, it also makes the early rounds of the majors somewhat boring. There is no parity in men's tennis at the moment and what reason is there to believe that change is coming?
Perhaps Tsonga or del Potro will find their best tennis and crack the Big Four in 2012. However, we saw no hint of that at the Aussie.
Maybe Kei Nishikori, Milos Raonic, or one of the younger players will turn into a Grand Slam threat soon, but again—there's little reason to believe in that based on their on-court performances.
There has to be change eventually, however you have to wonder if the remainder of the year will see the usual suspects in the semifinals time and time again, with maybe just one deviation somewhere along the line.