The on-court rivalry between Novak Djokovic and Rafael Nadal began at the 2006 French Open, when a 19-year old Djokovic had to retire from their quarter-final.

Sixteen years on, they are preparing for the ATP Tour Finals, where Djokovic has triumphed five times but Nadal is yet to win.

The pair have met 59 times in total, and Djokovic leads the head-to-head at this tournament 3-2.

BBC Sport looks at the key numbers that have defined their 16-year rivalry.