They call them: the “big 4”: Roger Federer, Rafael Nadal, Novak Djokovic, and Andy Murray.  These four have dominated Slam titles for half a decade with only one interruption: the 2009 US Open won by Juan Martin del Potro.  Had del Potro not been injured and required surgery in 2010, maybe there would be a top 5 with del Potro.

It’s claimed that men’s tennis has never been so top-heavy as it is now.   And this disguises something interesting at this year’s Australian Open.

The rest of the field is playing pretty good, too.

Of the top 16 seeds, players expected to get to the fourth round, only 3 players: Juan Monaco, Juan Martin del Potro, and Marin Cilic have lost.  The rest are still there.  And even there, two of them (Cilic and del Potro) fell only one round short.  Last year, it wasn’t nearly as good.  Seven of the top 16 players lost before reaching the fourth round, but only 3 lost before the third round (intriguingly enough, 2 of those 3 were Americans and the third was Gilles Simon).

Back up a decade ago to 2003.  Then, 9 of the top 16 seeds failed to reach the fourth round, but of those, 6 players didn’t make it to the third round.  This included fifth seed, Carlos Moya, 11th seed, Paradorn Srichaphan, 13th seed, Fernando Gonzalez, 14th seed Guillermo Canas, 15th seed Alex Corretja, and 16th seed, Sjeng Schalken.

So what’s the point?  The top 4 have been so good for so long that players underneath them have ceded that, and scramble to keep their ranks up.  These include players like David Ferrer, Tomas Berdych, and Jo-Wilfried Tsonga which have stayed in the top ten for 3 years.  Janko Tipsarevic worked his way to the top 10 back in 2011, and held onto that position in 2012.

It wasn’t so long ago, that players ranked below 5 were in a constant flux with players moving in and out of the top ten.  Today’s players are more professional than ever, and with it, have better training techniques, work on trying to stay healthy, and try to figure out how to make a dent among the very best players.  As they do this, they are making it tougher for those ranked outside the top 20 or so from making significant progress.

Of course, some progress is made.  Milos Raonic and Kei Nishikori have worked up the ranks.  Andy Roddick has retired.  Mardy Fish is still handling health problems.  So some players have faded while others take their place.

And frankly, these results may simply be coincidence because of the timing of the Australian Open.  The Aussie Open has become more true to form (when it used to be a title that random players did well) because players have had a chance to train, to rest and recover.  In the past, some just took time off, and didn’t take their training seriously.  When every player at the top is working hard in the off-season, this puts pressure on those aspiring to be at the top.  Today’s players also tend to play their best tennis on hard courts, because so much of the season is on hard courts.  With Rafa dominating clay, you better be able to play hard courts well if you want to be at the top of the ranks.