Roger Federer of Switzerland (L) hold his runner-up prize as Novak Djokovic of Serbia holds the U.S. Open trophy after Djokovic won their men’s singles final match at the U.S. Open Championships tennis tournament in New York, September 13, 2015.

Roger Federer wonders what might’ve been if only he’d converted any of those three break points in the last game of the U.S. Open final.

The victory is the 10th of Djokovic’s career in Grand Slam events, and he is 10-8 in finals.

The Swiss went 5-2 down in the fourth set, only to win the next two games and have three break points when Djokovic served for the match for a second time.

By triumphing in New York, the world number one tennis player became only the eighth man in the history of the sport to have double-digit Grand Slam titles. Federer beat Djokovic in the 2007 U.S. Open title match, one of his five championships in Flushing Meadows. Federer tried everything he can to hang in with Djokovic’s long rallies and using everything in his arsenal, including his new Saber method, he uses when his opponent serves. Unlike in 2011, though, he played in all four major finals this year. I don’t think I have done that before. “I’m pleased with where my game is at”, he said.

In the end, Djokovic handled everything in a thrill-a-minute final on a frenetic night.

But he failed to breach Djokovic’s formidable defensive skills, managing to convert just four of 23 break point opportunities. It was disappointing when something I said nearly a week ago came up on this weekend in a manner that was disparaging to the great Swiss champion. But, to be considered the all-time best, Djokovic has his work cut out for him.

A day after US Open women’s champion Flavia Pennetta dropped in a casual last mention that she was retiring, Federer teased the crowd of 26,420 about his future for a split second before making his plans clear.

Confronted with Djokovic’s unequalled ability to race along the baseline and contort his body this way and that, sneakers squeaking loudly as he changed directions or scraping like sandpaper as he slid to reach unreachable shots, the 34-year-old Federer found himself trying to put the ball into the tiniest of spaces.