He's been called "the great American hope," but his Grand Slam performances until Sunday have been just another choke.

Two things are markedly clear about Andy Roddick:

He's not a great champion like Pete Sampras, but he's also not Anna Kournikova, despite the Rolling Stone photo shoots.

He's more like Roger Federer. Tons of talent with an affinity for winning the minor tournaments and falling off his game at the end of majors.

But Sunday was different - the media darling's moment in the sun. He crushed clay-court specialist and world No. 1 Juan Carlos Ferrero in three waiting sets to win the U.S. Open in front of a highly supportive New York crowd.

But those expectations, the largest since a flashy, long-haired Andre Agassi first took the court, might be too much for the Nebraska native who is getting a full taste of the good life. Remember Jennifer Capriati? Admittedly younger, but, like Roddick, immature.

Roddick's serve is the best in the game, reaching 149 mph at Queen's Club this summer, tying the world record. But, the serve isn't everything in men's tennis. Just ask Mark Philippoussis and Greg Rusedski.

Roddick's forehand was his savior against Ferrero, winning almost every long rally with a winner from his strong side. The only true hindrance in his game, and a small one at that, is his backhand.

What the recently turned 21-year-old is really missing is the mental end of the game. He's too emotional. He gets too involved in the match, which drains him. And if a line call doesn't go his way, he's prone to melt down.

That weakness is what ultimately will keep the phenom from fulfilling all of his many expectations.

The good part for Roddick is he recognized the problem early and turned to the champion of mental tennis, Brad Gilbert, as his coach after he lost in the first round of the French Open.

Gilbert was never that great of a player, but he frustrated the likes of Jimmy Connors and John McEnroe plenty in their day. They hated losing to a junkballer like Gilbert.

He also refurbished Agassi's career and solidified his place as one of the best in the history of the game.

With Roddick, Gilbert focused on the smallest details.

No, he didn't force Roddick to break up with Mandy Moore, but he did make him ditch the Steve Spurrier visor which exposed his spiked hair for a trendier throwback mesh hat, trying to feed off the success of fellow mesh-ites Pharrell and Ashton Kutcher.

He also tried to persuade Roddick to keep his emotions inside and save them for the end of the match.

So far, the changes have brought success. He lost in the semifinals of Wimbledon and has won 37 of 39 matches since the coaching change, including 19 straight and five tournament titles.

But the real question is, how can he work with a little adversity? Roddick looked as soft as strawberries and cream when he folded against a superior Federer in the semifinals at Wimbledon.

Since that loss, Roddick has been golden this summer. He won the Masters Series tournaments at Toronto and Cincinnati and he's rolled through the U.S. Open.

Until the semifinals, when he was tested by David Nalbandian and prevailed.

This was his most impressive performance since his five-hour war of attrition with Younes El Aynaoui in Australia.

Roddick was down two sets and Nalbandian had a match point in the third-set tiebreaker. But A-Rod used his amazing serve, with consecutive aces at 138 and 136 mph, to come back and win the tiebreaker. He then cruised into the final behind his 38 aces, 6-7, 3-6, 7-6, 6-1, 6-3.

And now, with Pete Sampras retired and Andre Agassi and Todd Martin soon to follow, Roddick has been anointed the savior of men's tennis.

Mardy Fish, James Blake, Alex Kim and Taylor Dent will just ride his coattails.

It's just a matter of how long it will take until he breaks down again. Agassi did, McEnroe did daily and only Sampras could avoid it.

It's just a matter of time for Roddick.

Jon Styf, the great American hope of sportswriting, can be reached at styfjona@msu.edu.