When Novak Djokovic triumphed at Flushing Meadows last year, he surely thought the outright record for grand slam titles was all but his.
Yet just shy of a year later, Djokovic is still waiting for his 25th major win - and the one that would take him clear of Margaret Court, making him the undisputed greatest of all time.
He came close at Wimbledon, but Carlos Alcaraz ultimately had too much, with the Spaniard winning the final in straight sets.
Alcaraz, the 2022 US Open champion, will be one of the most likely candidates scrapping it out for Djokovic's crown over the next two weeks, along with world number one Jannik Sinner.
Djokovic avenged that Wimbledon defeat with a 7-6 (7-3) 7-6 (7-2) win over Alcaraz in the final of the Paris Olympics, with the 37-year-old ending his wait for a gold medal.
But while that gold is now hanging around his neck (or, in his trophy cabinet, which must be pretty big), it did not settle Djokovic's desire for that record-breaking major triumph. His next tournament win would also bring up his 100th career title.
Should Djokovic fail to defend his crown, though, it will be just the fourth year since he won his first major in 2008 that he has not won a grand slam in a season, after 2009, 2010 and 2017.
But what do the Opta statistics tell us about the key storylines ahead of the US Open?
Can Djokovic dominate?
Jimmy Connors, Pete Sampras and Roger Federer have won the US Open a joint-record five times each. Should Djokovic win, he will join that illustrious trio on five Flushing Meadows titles.
Connors has appeared in (115) and won (98) the most singles matches of any player in the Open Era at the tournament, but Djokovic (88) has won the most among active players and could equal Federer (89) for the second-most by defeating Radu Albot in round one on Monday.
Should Djokovic reach the second round, he will also match Federer's tally of matches played in the competition (103).
At 87.1%, Djokovic holds the second-best win percentage at the US Open in the Open Era of players to have featured in at least 30 matches at the event, after Sampras (88.8%).
The Serbian great, who became the oldest player to win the men's singles at the US Open when he succeeded at the age of 36 years and 111 days in 2023, has featured in the most men's singles finals in the tournament's history (10). He is the only player in the Open Era to have reached 10+ finals at multiple grand slams, having also done so at the Australian Open and Wimbledon.
Should he reach the quarter-finals, barring walkovers, Djokovic will surpass Federer (429) for the most matches played at grand slams in the Open Era. If he were to then reach the last four, he would be the first male to appear in 50 major semi-finals, and the second player overall after Chris Evert (52).
Connors (109) and Federer (103) are the only players to win 100 Tour-level titles, while Djokovic is chasing his 72nd hard-court title, which would take him clear of Federer (71).
Could the kids have too much?
Djokovic may have outfought Alcaraz at the Olympics, but that was only after he had been dispatched by the world number three at the All-England Club.
Alcaraz, who said he had played his worst-ever tennis during a shock defeat to Gael Monfils at the Cincinnati Open earlier this month, could become only the third player in the Open Era to win the men's singles title at Roland-Garros, Wimbledon and the US Open in the same year after Rod Laver (1968) and Rafael Nadal (2010).
Aged 21 years and 126 days, he would also be the youngest man to win a singles title at three grand slams in a calendar year. He won his first major title at Flushing Meadows two years ago, and reached the semi-finals last season, losing to eventual runner-up Daniil Medvedev.
Then there is the world number one, and top seed, Sinner. The Italian was forced to miss the Olympics due to illness, but after going out in the last eight at the Canadian Open, he returned to form with a sensational run to triumph in Cincinnati.
That was his fourth title of the season. Excluding team events, Sinner (23 years, 23 days) could become the youngest player to win five ATP trophies on hard court in a calendar year since Andy Murray in 2009.
Since the Australian Open switched to hard court in 1988, Sinner could become only the fourth male to win that competition and US Open in the same year, after Mats Wilander (1988), Roger Federer (2004, 2006 and 2007) and Djokovic (2011, 2015 and 2023).
Sinner has now won three ATP 1000 hard-court titles in total. Across the past decade, only three players have won more Masters titles on the surface: Djokovic (17), Federer (seven) and Medvedev (five).
The last top seed to lose in their opening match at the US Open was Stefan Edberg, who lost to Alexander Volkov in 1990.
Indeed, the US Open is certainly not a tournament in which you can confidently say "expect the unexpected" when it comes to major shocks.
Only two top seeds in the Open Era have been eliminated in the first round of the men's singles – John Newcombe (1971) and Stefan Edberg (1990). Andre Agassi is the last first seed to not reach the second week at the event, losing to Arnaud Clement in straight sets back in 2000.