This is one of those remarkable stats that’s been floating around for years, but it’s always worth repeating, especially after a weekend that saw Roger Federer win a tournament for the first time in 18 months and Tiger Woods being forced to withdraw in the middle of a round due to a back injury. Over his 16-year career, Federer, who has played almost 300 more matches than any active player, has never retired in the middle of a match. No other player in the top 25 has fewer than three career retirements, according to data on tennisabstract.com.

Here’s a list of how Federer’s retirements compare to his contemporaries and some past tennis legends.

Federer’s 1,154 matches are the most by any active tennis player. The rest of the top 10 in matches played — none of whom is within 290 matches of Federer — has an average of 12.4 career retirements. Those players: Tommy Haas (23), David Ferrer (7), Lleyton Hewitt (6), Nadal (7), Nikolay Davydenko (23), Tommy Robredo (9), Mikhail Youzhny (13), Tomas Berdych (9) and Jarkko Nieminen (15).

Okay, great, but what does it all mean? Is Federer tougher than Nadal because he’s never thrown in the towel during a match? Does Novak Djokovic’s 11 retirements make him less of a competitor than Andy Murray? Of course not, though that’s not to say the numbers are meaningless. The Djokovic retirement total was a blight on the early part of his career. And Federer’s non-retirement streak is still an impressive feat of durability, toughness and stubbornness, like Cal Ripken’s 2,632 consecutive games played. Call it another impressive statistic on a resume filled with them.