Djokovic's 2015 Among Best Seasons Ever

Immediately after Novak Djokovic's victory in the Wimbledon final over Roger Federer on Sunday, comparisons were being made between what Djokovic did to start 2011 and what he has done so far this year.

I wanted to take an in depth look at that comparison, but I realized that would almost be insulting to Djokovic. He isn't only having arguably the best start to a season of his career - he's having arguably the best start to a season ever.

I should clarify after using a loaded work like "ever". When comparing specifics of just a portion of a season, it becomes drastically harder to compare players from different generations. Although I am a firm believer that comparing a player's career from the 1970s with a current player is very doable, it isn't so simple when you are only comparing a portion of a season. So for this research piece, I only focused on results since 1990, when the Masters Series format was introduced.

I looked at how every year-end champion did from the start of the season to the end of Wimbledon and compared their results.

All ranking points are adjusted as best as possible to equal the
current ranking system. It's not perfect, but it was my best attempt.

Djokovic's 2015 season ranks at the top for ranking points earned to start a season as well as wins against top 10 opponents in that span. For total wins in such a span, Federer's 2005 season leads the way with 59 wins, but for win percentage, Djokovic's 2011 sets the top mark after winning 48-of-49 matches. In titles, Pete Sampras' 1994, Djokovic's 2011, and Federer's 2005 all have eight.

What Federer did in 2006 and what Rafael Nadal did in 2008 each rank among the top in several categories as well. Those six half seasons represent the best tennis has ever seen, so I limited the rest of my research to a more detailed breakdown of those six seasons.

The main problem with the stats in the table above is the limitation of the "top 10 wins" stat. That category treats a win over the No. 11 as equal to a win over the No. 111 and a win over the No. 1 as equal to a win over the No. 10. What's so magical about the top 10?

So I did a more detailed break down of the difficulty of opponents.

I looked at the ranking of each of their opponents and calculated the mean and median of their ranking. I also looked at what percentage of their opponents faced were ranked in the top 10, top 20, and top 30.

The two seasons that stand out for toughest schedule both belong to Djokovic. In his 2011 season, he faced the lowest ranked opponents on average, and had the highest percentage of opponents being ranked in the top 30. Yet that season, he had the best record of anyone going 48-1.

The 2015 season for Djokovic has arguably been the tougher of the two in terms of difficulty of opponent with the Serb facing opponents with a median ranking of 25. He has also had to face by far the highest percentage of top 10 opponents this season as well as the most top 20 opponents.

The only season that comes close in difficulty of schedule is Nadal's 2008 season in which he suffered seven losses before the end of Wimbledon and failed to collect 9000 ranking points.
Federer's 2006 season features one of the easiest schedules on this list, which takes away from the incredible results the Swiss posted in the first half of that season.

If the way to measure the greatness of a season is degree of success compared to degree of difficulty, what Novak Djokovic did in the first half of 2011 and so far in 2015 is by far the best tennis has ever seen. Djokovic this year has faced double the percentage of top 10 players that Federer faced in 2006 and has still managed a higher winning percentage, the same number of titles, and more total ranking points earned despite playing one less tournament.

If the current world No. 1 can keep up the pace for the rest of this 2015 season (which certainly seems possible since the rest of the season will be played on his favorite surface), we could be watching the greatest single season of tennis in at least the last 25 years.