NEW YORK -- The folks in Las Vegas who traffic in sports results are keenly aware of the value of the home-field advantage.
It is a powerful concept, as we saw at the recent London Olympics. UK Sport set a target of 48 medals, one more than was achieved four years ago in Beijing. The first went to cyclist Lizzie Armitstead, who was rabidly cheered all along the road-race course and came home with the silver.
When it was all over, Great Britain finished fourth in the overall medal standings, behind the United States, China and Russia, with 65. The gold-medal total -- 29 -- was surprisingly better than Russia's.
"This is our greatest performance of our greatest team at the greatest Olympics ever," enthused chef de mission Andy Hunt.
How did it happen? The home-field advantage.
Here at the U.S. Open, it's been a huge factor.
How else to explain what happened Saturday out on the Grandstand court? Nineteen-year-old Jack Sock, playing in only his third Grand Slam, gave No. 11 seed Nicolas Almagro (playing in his 33rd) all he could handle. The first three sets averaged 54 minutes each and required tiebreakers. Sock lost 7-6 (3), 6-7 (4), 7-6 (2), 6-1, a remarkable result for a guy ranked 231 spots lower than the Spaniard.
If you had been in that frenetic crowd in the sweat-drenched, jam-packed Grandstand, you'd know why.
"When you play a foreign guy on that small of a court and that intimate of a court, it's unbelievable," Sock said. "I mean, pretty much every point, you feel like you won the match. New York for the U.S. Open is definitely the best possible place to play tennis in front of a home crowd. The energy from the crowd it was a great feeling.
"That energy, definitely, you definitely get an adrenaline rush and maybe raise your game and hit some crazy shots that you may not hit usually."
Americans made a nice impression in Week 1. The doubles teams are doing phenomenally well. Stanford senior Mallory Burdette rode the wave of nationalism into the third round. Two-time NCAA singles champion and wild card Steve Johnson plays Richard Gasquet on Sunday for a spot in the fourth round.
Sock was one of four wild cards to make it through to the third round, an Open era record for any Grand Slam. One of them was Australia's Lleyton Hewitt, the 2001 champion. The other three were Americans: Sock, Johnson and the venerable James Blake. Coincidence?
Later Saturday, the Grandstand was packed again as Blake took on No. 15 seed Milos Raonic, a far tougher assignment than Sock's. Raonic came in with only a single career victory here in New York, but the 21-year-old Canadian missed the U.S. Open a year ago following hip surgery and lost in qualifying the year before. He is seen as a major player going forward, thanks to his gargantuan serve and well-rounded game.
Blake was something of a surprise in winning his first two matches. At 32, he came agonizingly close to retiring earlier this year when his right knee was slow to recover from surgery. A quarterfinalist here in 2005 and '06, Blake was the overwhelming sentimental favorite. But the crowd couldn't lift him high enough.
Not that it didn't try.
"Here we go, James [clap, clap, clap, clap, clap]," the crowd chanted again and again.
Blake managed to force a tiebreaker, but Raonic's serve served him well. There were four aces in that final session. Raonic won 48 of 54 points (89 percent) on his first serve, hit 29 aces and drilled one 143 mph.
"Today obviously wasn't a ton of fun," Blake said. "But I'm excited to be playing well enough to enjoy it."
Sam Querrey, too, showed signs that he is making progress. He played great tennis for two rounds before bowing out to Tomas Berdych in four sets.
How special was Sock's run here? He was trying to become only the third American teenager since 1991 to make the fourth round at the U.S. Open; the others were Michael Chang and Andy Roddick.
Sock had looks in each of the first three sets, but his best opportunity to take a decisive 2-1 lead came at 4-all in the third. He won the first three points on Almagro's serve and held three break points. The first two quickly evaporated, but the third required the best, sustained point of the match. Almagro took it when Sock sprayed a forehand long and wide. Sock stood on the baseline, breathing heavily in the heat, and you wondered whether he was fit enough to stay with Almagro. The answer came soon enough; Sock lost a one-sided tiebreaker and an even more lopsided final set. For the match, he converted only one of 11 break points.
Sock is only 19. He knows what's ahead of him. What has to get better?
"Everything," he said emphatically. "Get better at everything."