But the differences -- at least during Roddick's comprehensive 6-3, 6-3, 6-4 victory under the Arthur Ashe Stadium lights -- were far more apparent. Sock gave a fine accounting of himself, meeting the moment as an aggressor before a near-capacity audience. He held serve to open the match with a pair of booming aces, including a 124-mph missile on game point. He hit 16 winners in the opening set compared to seven for Roddick. And he played himself into a couple break chances early that could have turned the match, demanding Roddick conjure his best shotmaking in months to stave them off.
"I could draw so many parallels to what he was going through," said Roddick, whose No. 21 seed is his lowest at a major, "but I could also draw on my own experience a little bit."
Not unlike the co-feature match of Friday's night session -- where the seasoned if not sensational Maria Kirilenko outclassed game yet green New Jersey native Christina McHale -- Roddick's veteran understanding of the game's nuances was the difference. Roddick gained steam as the match progressed, beating back his opponent's aggressive play with powerful, consistent groundstrokes. Yet there was Sock, gold crucifix dangling outside his sweat-soaked adidas top, breaking Roddick's serve in the third and threatening to claw back into the match.
Two days earlier, Sock beat 97th-ranked Mark Gicquel for his first tour-level victory (in his third event). He only turned pro 40 days ago, after forgoing the academy route to instead lead Blue Valley North High School to four consecutive Kansas 6A state championships. Most of Sock's experience against professionals has come on the Futures circuit -- tennis' answer to Class AA ball -- which travels to outposts like Tamarac, Fla., Decatur, Ill., Chico, Calif., and Brownsville, Texas. Yet despite entering Friday's match with a ranking of No. 555, Sock is well known in tennis circles: He's won the boys' 18s national championship in Kalamazoo two years running -- which merits wild-card entry to the U.S. Open main draw -- he's been name-checked on Pardon the Interruption and described as the "future of American men's tennis" by the USTA.
Roddick turned 29 on Tuesday. There's not much left about him that hasn't already been said, written or tweeted. His career is a case of perverted dramatic structure: climax in the opening act. He's spent most of the past decade trying to reclaim the dizzying heights of 2003, when he captured his first and only major here in Queens. In 2009, he hired Larry Stefanki to coach him, and the improvement in his tactics, fitness and all-court game were palpable: a run to the Aussie Open semis, a title in San Jose and a spirited but ultimately tragic run to the Wimbledon final, where he lost 16-14 in the fifth to Roger Federer. Roddick's record at the eight majors since has been erratic, including a second-round defeat at last year's U.S. Open and just one quarterfinal appearance. An unbecoming loss to Philipp Kohlschreiber last month left him outside the top 20 for the first time since he was a teenager. "I'm not gonna sit here and pretend I'm in championship form right now," he said after Wednesday's match.
Yet he soldiers on, with a third-round match against France's Julien Benneteau on tap Sunday. When Venus Williams withdrew from the tournament Wednesday, Roddick was asked to reflect on his longtime cohort.
"My memories are when we're 10 years old and we're on the courts next to each other and it was all ahead of us," he said.
Those halcyon days have long faded into the past, but Roddick is determined to make the most of what's left of the present.