By Andrew Burton

Congratulations to Stan Wawrinka, who joined an exclusive club not too long ago.

I refer, of course, to ATP players who achieve a career high above 4000 ATP Ranking Points.

(Ed note: I’m sure that’ll be Stan’s abiding memory of last weekend).

Stan will be 29 in March of this year. He reached his first Major semifinal last year at the US Open, and had to beat the top 2 seeds in Melbourne to clinch his first Major title in his first final. It’s a great personal story – although Stan appears bemused by the number of people who now say they confidently predicted his eventual success. But focusing on an individual’s great achievement means we continue to ignore the deeper undercurrents in mens’ tennis. And when you look at the data, there’s only one conclusion.

An ATP Dark Age is coming.

Stan is the first player since Robin Soderling to break through the 4000 point mark. Like Stan, Soderling was a comparatively late bloomer: he first exceeded the 4000 point level in March 2010, at the age of 25. In fact, going back to the start of 2008, a span of six years, only 5 players have reached a career high of more than 4000 points: Jo-Wilfried Tsonga, Juan Martin Del Potro, Gilles Simon, Robin Soderling and Stan Wawrinka.

The period from 2000 to 2007 was very different. More than 23 players pushed themselves into the contenders’ ranks – an average of 3 per year. And many of these players were in their teens or early 20s. 5 players made their breakthroughs as teenagers: Lleyton Hewitt, Andy Roddick, Rafael Nadal, Novak Djokovic and Andy Murray. Three made their mark as 20 year olds: Marat Safin, Roger Federer, and Juan Martin Del Potro. This chart shows all 28 players, with their peak ranking points plotted against their breakthrough date:

There are three sets of players in the chart: Gen Guga, Gen Fed, and Gen Rafa (for generations). Roger Federer was born in August 1981, Nadal in June 1986. Their birthdays are about 5 years apart. Players born between January 1984 and November 1988 are in Nadal’s generation. Those born between March 1979 and December 1983 are Generation Fed, and anyone born earlier is Generation Guga (for Guga Kuerten, born in September 1976).

Stan Wawrinka may be Roger Federer’s team mate, but he’s squarely Generation Rafa. You could call him the 12th member of his graduating class. Generation Rafa was about as productive as Generation Fed: 14 players graduated from that class. Both “classes” have a mix of players, some of whom made their move at a young age, some in their mid-twenties or later. I’ll say more about that in a minute.

Let’s move forward in time. What can we can call the “class” after Generation Rafa? Add the same period between birthdays and you get to April 1991. Let’s call the top players born between December 1988 and September 1993 Generation Grigor, in honor of Grigor Dimitrov, whose birthday falls pretty close to the middle of this group of players (Dimitrov’s birthday is May 16th 1991.)

No-one from Generation Grigor has “graduated” – reached a career high of more than 4000 ATP Ranking Points – yet. In fact, only 13 players in this group has even made it into the ATP top 50, and only one – Milos Raonic – has spent any time in the ATP top 10.

Now, Wawrinka’s recent heroics probably have you growling “yeah, but… no, but… doesn’t Stan prove that a player can break through at any age? Give these guys time. Why does it matter how old you are when you reach some arbitrary level set by a member of the Changeover writing staff?” Good point! So let’s look at a chart of the same players, but now sorted by age at breakthrough:

Of the players on this chart, only two who broke through after they were 21 – Gaston Gaudio and Stan Wawrinka – won any Majors. And both those guys benefited from higher ranked opponents getting into physical difficulty in the Final.

The multi slam winners and perennial contenders – not just the Big 4, but Lleyton Hewitt, Andy Roddick, and Marat Safin – all graduated early. Remember, we’re not just talking about the unquestioned elite of the Open Era: we’re also talking about players whose Hall of Fame credentials aren’t fully established. And behind them come a group of good mid tier guys – all of them far more successful, to date, than Generation Grigor and those who have come after:

I put a version of this chart in my previous article at The Changeover on this topic last November. I’ve highlighted two players above: Wawrinka, now in the mid tier of post 2000 players, and Dimitrov – who, despite reaching the quarter final stage in Melbourne, is still a long way off from graduating.

This plays into the wider picture of the 2014 ATP in several ways. First, if you look at the top 10 and top 50 since 2000, here’s what you see:

Since the start of 2007, the average age of an ATP top 50 player has gone up by over 3 years. That’s an astonishing change. And we know that the ATP isn’t stocked with strong players under 21. There’s nothing that suggests that this trend will slow or reverse.

There’s an even more powerful implication in this data. It is the nature of sport that the old give way to the young. Fans of the WTA may have grumbled at those who loudly boasted of an ATP Golden Age, but no-one could dispute that the WTA has a terrific roster of players in their early 20s and younger.

But Generation Rafa is playing into a vacuum. Generation Fed is in the process of retiring. 8 of the 14 members of this class have already retired: of those still playing, only one (Federer) is remotely a threat to win another Major.

And there’s no-one from Generation Grigor who’s taken their place yet. Some commentators labelled the early to mid 2000s a weak era, and the last five years a golden one. Yet the golden era has a tin one to follow.

As Murray, Djokovic and Nadal add to their haul of Major titles, the evidence shows that the players that came after them are an order of magnitude weaker than those that came with them and those that came before them.

And when Generation Rafa begins to retire? Well, someone will have to win Major titles. 128 players will enter, and one will win. He’ll be rightly praised for his achievement. We can only hope that he’ll have played high quality tennis, but the omens aren’t good.

Call me Cassandra if you like. The ATP Dark Age is coming.

Andrew Burton has written for tennis.com, and has covered the Indian Wells Masters 1000 on occasion. He likes to give short answers to your questions on Twitter.