At this point, the only thing I write about on this blog anymore is the GOAT debate. It is a fascinating topic right now as Djokovic, Federer and Nadal now hold almost every record in tennis, yet are all still active as of right now.
One of the most challenging parts of GOAT debates is comparing players from different eras. For example, is it more impressive to win a major title or finish the year ranked No. 1 in 2020 than in 1973? I've tried tackling this question in a few different ways. The primary way is to simply assume that it is equally difficult to win majors in any era. I've defended this approach for a long time, because in every season, there are four major titles that can be won and you have to be the best out of 128 players over a two-week span in order to win a major.
I still think this is fundamentally the correct approach, but there is some room for nuance. It is impossible for the level of competition among the top players to be exactly equal every single year. However, measuring the difference is virtually impossible.
I've tried to use a new method to measure how strong a given year's level of competition was. Almost all majors are won by players in the top-10, and making the year-end top-10 is fairly easy for any serious GOAT candidate. So for this measurement, I've limited my analysis to top-10 players.
The first step is to assign points to each player for where they finish each year of their career in the rankings since the 1973 season. They get 15 points for finishing No. 1, 14 points for finishing No. 2, etc. with the cut off at the top-10. This gives each player a sum of points that approximates somewhat accurately where each player ranks in the all-time standings. These were the final rankings using this method.
1. Roger Federer
2. Rafael Nadal
3. Jimmy Connors
4. Novak Djokovic
5. Andre Agassi
6. Ivan Lendl
7. Pete Sampras
8. Boris Becker
9. John McEnroe
10. Stefan Edberg
This is certainly not the correct top-10 in the GOAT rankings, but it is a good-enough approximation. The main reason this method works is that it does not take into consideration which era a player is from, but compares each player against their own era to determine their value.
The next step is to measure the career accomplishments as defined above of all of the players in the top-10 of every season. The season with the top-10 that had the greatest career accomplishments could be considered the best year in tennis history. A better way to measure this could easily be created, but this should create a useful starting point. Here are the final rankings I got for the best years in tennis history.
1. 2013
2. 2015
3. 2009
4. 2014
5. 2008
6. 2012
7. 2010
8. 1992
9. 1985
10. 1987
It is no surprise that 2013 topped the list. Although the order of the top-10 that year is a little surprising, the list of players that compose the top-10 is very strong: Nadal, Djokovic, Ferrer, Murray, Del Potro, Federer, Berdych, Wawrinka, Gasquet and Tsonga.
The earliest season to make the list is 1985, which also had a very strong top-7 that was made up of: Lendl, McEnroe, Wilander, Connors, Edberg, Becker and Noah. In 1987, those same seven players were all in the top-10 along with Pat Cash.
The three years that Federer most dominated tennis were 2005-07. The 2007 season ranked as the 12th best in tennis history, while 2005 ranked 14th and 2006 was all the way down in 35th place.
Djokovic's peak years were from 2008 to 2015. All of those seasons rank among the 11 best seasons in tennis history.
The seasons from 2016 to 2020 will likely move up on the list since the players ranked in the top-10 in those seasons have not finished racking up career accomplishments. A season that has Tsitsipas, Zverev and Medvedev in the top-10 will likely look a lot stronger when we look back 10 years from now.
I've spilled quite a bit of ink in the past comparing what Djokovic did in 2015 to what Federer did in 2006. I think without even analyzing the strength of competition, it is already clear that Djokovic had the better season. However, when you consider the strength of competition that the two players faced, the gap grows much bigger. The 2015 season ranks second in the open era compared to the 2006 season which ranks 35th out of 48 seasons.
The biggest take away from this study is to reconfirm what has been already been proven several other ways: the competition that Federer faced in his peak was not nearly as strong as the competition Djokovic faced during the peak of his career. While this doesn't take away from the records that Federer has accumulated during his career, it does show that Djokovic's grand slam titles and weeks at No. 1 during his career are more impressive than the ones that Federer has accumulated.