Do top tennis stars hog titles or motivate others?

Supposing - and this is a colossal, absurd "if" - that Roger Federer hadn't been on the scene these past seven years. Would Rafael Nadal have won the U.S. Open by now? Would Andy Roddick have added a second major title to his 2003 Open championship?

And, just as illogical, would this year's tournament have the same spectator lure if Federer's elite peers (most prominently Nadal, at other venues) had not recently found ways to storm Federer's castle a bit, creating the new drama of whether Federer's record run of 16 career major championships might at last have shuddered and stalled?

"I will give you my pat line," said Jimmy Connors, who could argue he might have won more than five U.S. titles if not for contemporaries such as John McEnroe and Bjorn Borg three decades ago.

"If Roger wasn't there, Andy might have won five Grand Slams," said Connors, who is working this year's Open as a commentator for the Tennis Channel. "But, on the other hand, if Andy wasn't there, maybe Roger wouldn't have won so many Grand Slams, either. To have somebody like that to shoot at . . You know, McEnroe chased Borg, I chased Borg, I chased Mac, Sampras chased Agassi, Agassi chased Sampras . . . "

In "Unmatched," the documentary for ESPN's 30 for 30 series that will air Sept. 14 centering on the long-running Martina Navratilova-Chris Evert rivalry of the 1970s and '80s, Navratilova submitted, "We'd have both won more Slams if it hadn't been for the other."

Most likely. Except that both women spoke in the film of finding motivation in the other's challenge.

Ivan Lendl, three times the Open champion toward the end of the Connors-McEnroe era, agreed that "the odds are against" Roddick winning another major, except that "weird things happen in tennis." And he cautioned against fairly widespread expectations that Nadal is on the verge of taking his first U.S. trophy, noticing how "Roger is gaining" on Lendl's own eight consecutive U.S. Open final appearances, the modern tournament record.

"In my opinion," Lendl said, "this will always be the hardest [major] for Nadal to win. I still think he will win [at some point]. But it's saying a lot" to anticipate the Spaniard's imminent breakthrough at Flushing Meadows.

More to the point, Lendl said, the Nadals and Roddicks and last year's Open champion, Juan Martin del Potro (currently rehabilitating a surgically repaired wrist), ought to be seeing Federer's presence as a glass half full. "You could look at it as a great time to be playing," Lendl said, "because these other guys clearly are better because of Roger."

And that, Connors said, is the idea. "Was McEnroe unlucky that he played with me and Borg and Lendl and those guys?" he asked. "Was Sampras unlucky that he played with Courier and Agassi and Chang? No. Isn't that what it's all about - to play guys that bring you the competition on a daily basis, and you've got to figure out a way to do your best?

"You can't sit back at the end of your career and say, 'Gee, if it wasn't for Federer, I might have won five or six Grand Slams.' You go through the rest of your life with a 'what if.' That's brutal."