How U.S. men are faring at Open depends on perspective

We're deep, noted Sam Quer rey yesterday, a few hours before John Isner, the man who dug down deeper than any player ever to win a fifth set, 70-68, two months ago at Wimbledon, last night challenged Mikhail Youzhny and some tired-but-true perceptions about American men's tennis.

Isner, 6-foot-9, fired aces and had not only his size but the size of the crowd at Arthur Ashe Stadium going for him when he came back from down two breaks in the second set and won the tiebreaker.

But Youzhny cranked up his serve inthe third-set tiebreaker, broke Isner in the third game of the fourth set and made the vast majority of the shots in the match against a player who needed 33 aces for 63 winners. The 12th seed won 6-4, 6-7 (5), 7-6 (5), 6-4 to reduce the American male survivors of this U.S. Open after three rounds to Querrey and Mardy Fish.

"You know, after this tournament we'll have four guys in the top 20 with Andy [Roddick], John, Mardy and myself," Querrey said after putting away Nicolas Almagro in three sets. "I don't think we've had that in a long time [actually since July 2006].

"We might not have a guy in the top five, but four in the top 20 is pretty good."

Indeed, according to the World Bank, yesterday at 4 p.m. there were 6,697,254,041 people in the world, only 307 million of them American. But when you consider we are the nation of Pete Sampras, Andre Agassi, John McEnroe, Jimmy Connors and Bill Tilden and that of the 38 nations represented in this men's U.S. Open field, our 15 entrants are more than anybody's including France (14) and Spain (13), the U.S. has become a dreary also-ran.

Having four guys ranked 10-20 isn't going to grow the game here like having one guy No. 1 or No. 2. Somehow, for all the money parents in one of the richest nations on earth spend on tennis lessons, the runaway two best American players of this generation were taught by their father on a public court in a California ghetto.

Granted, the Williams sisters were a great genetic accident, but as good as the odds would seem that once-a-generation we could come up with another, nevertheless our jollies come round-by-round through players unlikely to win this event any year soon.

"As of now it's myself, Mardy and Sam [for Davis Cup]," Isner said. "I believe my flight [for Colombia] is in six days.

"Maybe they won't be on my flight. Maybe they'll be playing on Saturday and Sunday."

Stanislas Wawrinka, not No. 4 seed Andy Murray, is next for Querrey after yesterday's upset, quite a break for the American who now just might reach his first Grand Slam quarterfinal at age 22. Isner, 25, who beat surgery on a right ankle ligament that threatened his Open, said he played without pain but also without "pop" in his shots.

Fish, a quarterfinalist here in 2007 in his best-ever Slam run -- the farthest an American has gone since Andre Agassi challenged Roger Federer in the 2005 final, is playing better 30 pounds lighter.

Do you believe in miracles?

"I honestly think everyone's kind of rough on [Fish]," Querrey said. "They make him sound like he was just fat before this year and that they're surprised he could play.

"It's obviously helped him, [but] the guy used to be 17 in the world. He's not like a different player."

If only Fish could beat third-seeded Novak Djokovic today and prove otherwise.

jay.greenberg@nypost.com