Holds and Breaks – The stat that separates every year-end World No. 1 from the rest of the field

While forehands and backhands might form a big part of any technical tennis discussion, when you strip the game down to the basics it all comes down to the serve. If you are holding serve (or conversely breaking serve) more than your opponent, chances are that you will win.

In the series called 'Holds and Breaks', we take an analytical look at various tennis phenomena through the statistical lens of holds and breaks. And here, we are going to explore what it takes to be the very best in the world.

We have looked at every year-end ATP World No. 1 so far in the 21st century, and noticed that every one of them has achieved at least one of two things during the year he finished on top. Yes, there's a pattern that has been observed in all 19 year-end World No. 1 finishes spanning six different players.

Every player to finish a year as World No. 1 this century has finished in the top 5 for either service games won percentage or return games won percentage, among all players that have played 30 or more matches in that year.

Every year-end World No. 1 this century has finished in the top 5 for either service games won or return games won that year

This goes to show that to be the best, you have to really stand out at either holding your serve or breaking your opponent’s serve, or both. There have been five instances where a player has finished top 5 in both holding and breaking for the year, and these were all particularly impressive years – Roger Federer in 2006, Rafael Nadal in 2008 and 2013 and Novak Djokovic in 2014 and 2015.

Novak Djokovic in 2015

When you think about it, this is really quite an incredible statistic. You will always have players like Ivo Karlovic, John Isner, etc. racking up incredible serve numbers, and on the flip side you will often have claycourters like Guillermo Coria and Diego Schwartzman posting incredible return numbers. But every year-end No. 1 still manages to find their way into the top 5 in holding and breaking numbers.

It is not enough to do both fairly well. Tennis is a game of holding and breaking serve, and to be the best, you have to stand out in at least one of these departments.