A History of Men's Professional Tennis (with Elo Ratings!)

The history of men’s professional tennis in the Open Era has been rich, vivid and in many ways epic. The Borg vs. McEnroe rivalry in the 70s. The emergence of Lendl, Becker and the Swede duo of Edberg and Wilander in the 80s. The American golden era of Pete Sampras, Andre Agassi and Jim Courier in the 90s. A period of contention among promising players in the early 2000s (Hewitt, Kuerten, Ferrero, Roddick, Safin). And finally the Big 4 era of Federer, Nadal, Djokovic and Murray redefining a new level of dominance.

How can we quantify the heights that we have seen in history, and evaluate just how dominant these players were? And who had the edge during the most intense years of their rivalries? I sought to answer this question by charting every ATP player’s Elo rating over time.

Elo rating is a system originally used to rate chess players, but has been utilized in other disciplines. In this system, a player rating increases if he wins, and decreases if he loses. How much the rating changes depends on the opponent; ratings don’t change much if it’s an expected outcome, but changes at a larger scale if there’s an upset. The Elo system I built backtested the last 46 years of ATP tennis matches to determine the optimal rating adjustments to make after every match. If there’s interest, I will write a post detailing that methodology.

Because players perform so differently on surfaces, I have created an overall Elo rating as well as an Elo rating on hard, clay and grass (carpet appears to be a thing of the past). With that, we can roll back the years and narrate the history of Open Era Men’s Tennis. Let’s go.

2003 - Present: The Big 4 Era

The Big 4 Era is truly a golden period of men’s tennis history - an extremely competitive and dominant period of men’s tennis. All 4 had the highest Elo rating at some point, and all 4 surpassed 2500 in their Elo ratings at some point - no other player reached that mark. A few remarks on each player:

• Roger Federer: Completely dominant until 2008 while the rest of the Big 4 were still developing. Regained the top position in 2009-2011, 2012, and most recently in 2017-2018 with his run of 3 majors in 12 months.

• Rafael Nadal: Although strongly considered in the GOAT (greatest of all time) debate, Nadal has only been the highest Elo rated player for very brief moments in his career, in 2008, 2010 and in 2013, likely due to his inconsistent performances on hard and grass. His slump in 2015-2016 put him at far lower ratings than the Big 4, due to his frequent defeats to lower rated players.

• Novak Djokovic: If we were to determine who was the most dominating player at any point in history, this chart gives the answer away. Djokovic in early 2016 is the highest rated player in tennis history, and that's no surprise. He had won 4 of the last 5 majors, the last 5 Masters tournaments (including the World Tour Finals), and top-10 players 32 times in the last 12 months.

• Andy Murray: While some tennis pundits only think of this era as the “Big 3” and not consider Murray in the conversation, his Elo rating suggests that he was never very far behind Federer, Nadal, and Djokovic. His dominant run in late 2016 to #1 in the world also put him as the #1 Elo rated players for a brief period.

Examining hard, clay, grass court Elo ratings also yields interesting insights. Some key takeaways:

The Big 4 appear to be the most even matched on hard courts. There were eras in 2008-2009, 2012 and as recently as 2019 (with the exception of Andy Murray) where their hard court Elo ratings were virtually indistinguishable. It’s pretty safe to say though that Djokovic had the edge on hard courts in the 2010s.

Not surprisingly, the King of Clay (Rafa Nadal) led the Clay Elo ratings for most of his career. The only time where he lost his advantage was during his slump in 2015-2016, when Djokovic was the leading clay court player (indeed Nadal was 0-3 on clay against Djokovic during that span)

On grass, Federer (again unsurprisingly) dominated until 2013, when Djokovic & Murray emerged as genuine contenders. Nadal attained the top Elo spot on grass after winning Wimbledon in 2008, but has since been a fairly weak grass court player since 2013.

1999 - 2004: The Transition Period

Before the Big 4 emerged and Federer dominated tennis in the mid-2000s, there was a period where there was no clear dominant player. Gustavo Kuerten, Lleyton Hewitt, Andre Agassi, Marat Safin, Juan Carlos Ferrero and Andy Roddick all were world number 1 at some point between 1999 and 2004. Looking at our Elo ratings, it seems that Hewitt & Agassi were the most consistent top performers during this era. But Federer’s rise from 2002 onwards left his fellow competitors in the dust.

The 1990s: The Sampras (& Agassi) Era

In the early 1990s, veterans Boris Becker and Stefan Edberg vied for supremacy against the upcoming young guns of Pete Sampras, Andre Agassi & Jim Courier. In fact at one point in 1992, all 5 players were within 100 Elo points of each other (which implied at most a 65/35 win probability margin)! Eventually, Pete Sampras emerged from the pack and was the leading player in the 1990s.

That said, Andre Agassi had several short stints where he challenged Sampras at the top, most notably in 1994-1995 (he won the US Open & Australian Open in succession), and 1999-2000 (he won 3 of the last 4 majors during that time).

Also noteworthy is that while Pete Sampras had the most grand slams at the time of his retirement, his all time high Elo rating was only in the 2200s, far lower than the peaks that other all-time greats achieved. This suggested that while he was year-end No.1 for 6 consecutive years, he never reached the level of dominance that other legends achieved.

The 1980s: The Era of McEnroe, Lendl and Becker

After Bjorn Borg retired in 1981/1982, John McEnroe & Ivan Lendl emerged as the top players in men’s tennis. While Lendl had a consistent & long career at the top, remaining the highest rated Elo Rating as late as 1990, McEnroe attained one of the highest Elo Ratings in history (only behind the Big 4) in 1984 and 1985, mostly driven by his 42-match win streak and 82-3 season record in 1984.

Other observations: Boris Becker reached his top Elo Rating in 1989 by winning the final 2 majors of the season. Mats Wilander & Stefan Edberg were the highest rated player at some point in their careers, but only briefly and never reached the ratings required to be sustainable at the top.

The 1970s: The Decade of Connors & Borg

Jimmy Connors was the clear No. 1 player in the early 1970s, followed by Bjorn Borg who led the latter half of the decade. John McEnroe was always close behind, especially in 1979, but it wasn’t until 1981 that McEnroe finally overtook Borg and ushered in a new era.

Author’s Note: I would not compare the Elo ratings of the 1970s to other eras, due to the fact our data source only has match results since 1974. A lot of top players, especially Connors and Ilie Nastase, were strong players before 1974. It is likely that our system is underestimating their true Elo Rating as of 1974 (i.e. our priors are inaccurate)

Future Posts

With this Elo Rating methodology, we can delve deeper into many aspects of men’s tennis history. To name just a few:

• Who are the best hard / clay / grass court players of all time?

• How are emerging superstars performing compared to past all time greats (in terms of age or matches played) ?

• What’s the implied win probability between player A and player B?

Stay tuned for more posts as we dig deeper into this Elo rating data.

Special Shoutout to Jeff Sackmann’s Github Repo for having clean, extensive ATP matches data. This blog post would not have been possible without this data source.