NEW YORK -- They were born six weeks apart in 1981 -- very far apart -- in Basel, Switzerland and Saginaw, Michigan.
On Monday night, Roger Federer and Serena Williams, the reigning royals of US Open tennis, were scheduled to play on Arthur Ashe Stadium court. Federer has won here five times, more than any of his active colleagues. Serena is on the board with four titles, twice as many as the next woman in line -- her sister, Venus.
And, at work beneath the pomp and circumstance of opening night at the 2013 Open, there was an even larger subtext. Not only are Federer and Williams the biggest producers at this event at the Billie Jean King National Tennis Center, they are the finest players of their generation. Federer has won an all-time record 17 Grand Slam singles titles; Serena has won 16.
Who will wind up with more when they play the James Blake card and finally retire? Most folks inside tennis would take Serena.
Predictably, she took down spirited 2010 French Open champion Francesca Schiavone 6-0, 6-1 in a match that required only 60 minutes.
What did Schiavone think when she first saw the draw? "Oh, s---," she said afterward. "But it's normal. She has two legs; I have two legs. Two arms. We are the same. We are human."
Still, "she was much better today than me," Schiavone concluded.
Federer wasn't quite so lucky in his match with Grega Zemlja of Slovenia. At the end of a beautiful day, rain moved into the metropolitan area and the match was suspended until Tuesday.
Federer, at 32, has seen his ranking fall to No. 7 among ATP World Tour players. That's the lowest it has been in more than a decade.
"No. 7 I don't think is a huge drop from No. 4, but people are going to say what they like," Federer said before the tournament. "Important is that I concentrate on my game and that the passion is there, that I work the right way, that I'm prepared and then feel like I can win a tournament."
There are few who see Federer as the eventual champion here -- the oddsmakers have installed him as a 12-to-1 longish shot. It will be an achievement in some minds if he beats potential third-round opponent Sam Querrey and eventually advances to the quarterfinals to book a 32nd career match against Rafael Nadal, who hasn't lost on hard courts this year.
When he was winning three majors a year (as he did three times in four years from 2004-07), the only question was who Federer would meet in the final. Now, he more often departs in the semifinals, or earlier. This year at Wimbledon he was stunned by Sergiy Stakhovsky in the first round, the earliest he has exited a major in more than a decade. Of the past 14 Grand Slams he has played, Federer has won only one, last year's Wimbledon.
Serena, although she will turn 32 next month, has won seven for her past 16. She is the oldest No. 1 singles player in the history of tennis.
Serena comes in with a rare problem: overplaying this summer. The final at Cincinnati was her 10th match in 15 days, and frankly, she looked tried losing to Victoria Azarenka in the final. She has been harried by a sore forearm and abdominal muscle, but she pronounced herself fit after a week off.
"I feel great," Serena said. "I feel completely recharged. To play more matches now later in my career than sooner, it's interesting how good I feel."
It was interesting how great she looked against Schiavone. Even with Schiavone fighting to stay in the points, Serena won 52 of 75 played. She is now 66-9 in US Open matches. Federer is 65-8; his winning percentage is merely one-one hundredth better.
When Serena was asked if winning her second major of the season would make it "great," her answer could have come from Federer, too.
"No," she said emphatically. "I don't need to do anything. That's the beauty of my career. I don't need to do anything at all.
"Everything I do from this day forward is a bonus."
Federer probably feels the same way. The good news for Fed fanatics? He said his chronically bad back -- which bothered his movement (and confidence) earlier this year -- is manageable for the moment.
"I really hope from my side that I can make it," Federer said of the quarterfinals and another date with Rafa, which would be their first at the US Open. "That's really my focus there."
A few paragraphs later, he realized that didn't sound quite right coming from the King of Slams and amended his thought.
"Clearly, when I come here I don't just look at trying to make quarters," Federer said. "I'm clearly trying to win the tournament, but it starts at the very beginning."
That's more like it. It's still exceedingly early, but for Federer and Williams, so far so good.