NEW YORK - What does age matter in the great scheme? One day you're 29. The next you're 30. Maybe the brief step is difficult to accept psychologically, although for Andy Roddick that would seem improbable.
But it doesn't make much difference how you play the game, on the court or off.
On Tuesday, in the sun and breeze, with massive Arthur Ashe Stadium either half full or half empty - depending on one's viewpoint - Roddick played his final tennis match as a 20-something.
The next time he's on a court at the U.S. Open will be Thursday, the day he turns 30.
His farewell to the 20s was an efficient 6-3, 6-4, 6-4 victory over a 21-year-old from Tennessee, Rhyne Williams, who perhaps someday will be the greatest American player, which Roddick was. And, in a way, still is.
You've heard it so many times: Age is a number. So is one's seeding, which for Roddick at this Open is 20, low for a man who always seemed ranked among the Top 10.
Injuries have brought him down, caused him to miss numerous events and reduced his effectiveness when he did play.
Roddick won the Open in 2003, the last U.S. player to take any Grand Slam, and if not much is different from one day to the next, there were massive alterations during a nine-year period.
For Roddick. For tennis.
"The game completely changed,'' Roddick said. "I was able to kind of recognize it. It's funny, because the things I feel like I get criticized for have kept me around a lot more than my contemporaries."
He meant modifying his style, developing a passable backhand, working on quickness, emphasizing agility over power.
He meant Marat Safin and Juan Carlos Ferrero, both of whom, now 32, are retired.
"I saw the way the game was going,'' said Roddick, who had the giant serve and the huge forehand - and originally not much else. "You have to get stronger and quicker. I don't think there was much room for a plodder who could hit the ball pretty hard."
There's always been room for Roddick, whose innate intelligence has been a joy in interviews even when his game didn't match his wit. He would predict the NBA draft selections, discuss politics on the men's tennis tour, offer self-deprecating humor and give coherent analyses of why he might have lost or Roger Federer had won.
Who, what, when, why? Roddick never hesitated to give an opinion. Or an explanation. Three times he reached the Wimbledon final, each time to lose to Federer. The first, in a postmatch interview broadcast through the stands, Roddick said, "I threw everything at him but the kitchen sink, so I went back to the locker room and tried to get the sink.'' The crowd roared.
So Tuesday, with a reference to those defeats and to Andy Murray's loss to Federer at this year's Wimbledon, someone asked Roddick if a loss could change the way the public views a player - and the way a player views himself.
"I think any sort of positive or negative on a big stage when eyeballs are on you,'' Roddick observed, "people form opinions. ... I think you get a pretty good reading of someone in tough moments. I can't really speak (about) Andy and what he's going through, but, you know, I don't remember much about the postmatch stuff from Wimbledon. But I guess people liked it back then.
"It wasn't something I was thinking about. I was just kind of reacting to what was in front of me."
Now so much is behind Roddick, and maybe still ahead. The mixture is of reality and hope, the same as that for most athletes. You compete, and then if everything goes well, you compete again.
"There is no acceptable result,'' Roddick responded when asked if making the second week of the Open could indeed be just that.
"You play your second round, try to win your second round. You go as far as you can. I don't think we think of it in the context of what's acceptable and what's not. You play a match to try and win a match."
The idea persists that if Federer hadn't come along when he did - at 31, a year older - Roddick might have won multiple Grand Slams. After all, he did lose to Federer in four finals, including the 2006 U.S. Open. Roddick doesn't think that way. He appreciates Federer's brilliance.
"I was never off Roger's bandwagon,'' said Roddick when the subject of Federer's return to No. 1 in the rankings was broached. "I'm not surprised to see him back. Novak (Djokovic) was playing unbelievable last year. Roger was just a little unfortunate. It's not a story for me, because he never stopped being the greatest."
Andy Roddick never stopped being himself, and for that American tennis, all tennis, is terribly fortunate.