Howell played in his first PGA Tour event at 17 and finishedT-2 in a Nationwide Tour event while he was still at Oklahoma State, where he captured the 2000 NCAA championship. In his second season on the PGA Tour, he won the Michelob Championship and finished ninth on the money list. He hasn't been as good since, winning only one other event, the 2007 Nissan Open. Judging by this photo from one of his first pro events in 2001, he also hasn't gained much weight through the years.
Chad Campbell
Remember Shaun Micheel's one shining moment at the 2003 PGA Championship? Well, that came at the expense of a young Mr. Campbell. But never fear, golf pundits said. Campbell, then 29, would have many more major chances (Sports Illustrated even put him on its cover, calling him the "Next Big Thing"). Nearly a decade later, other than a playoff loss at the 2009 Masters, that hasn't turned out to be the case.
Ricky Barnes
When the University of Arizona star captured the 2002 U.S. Amateur at Oakland Hills, Johnny Miller hailed him as a potential next Arnold Palmer of the game, noting both his looks and his bold style of play. That prediction fell flat, but Barnes, along with other guys like Tiger Woods, did help usher in a wave of young and fit golfers on the PGA Tour.
Bill Haas
Haas was a star at Wake Forest, shattering Luke Donald's NCAA record for scoring average his senior season (2003-04). Sports Illustrated pegged him as the best American golfer under the age of 30 while he was still in college. He signed a huge endorsement deal with Titleist upon turning pro, and then ... not much. At least, that is, until 2010 when he won twice and followed that up with his lucrative win at the 2011 Tour Championship (left), which helped him earn the FedEx Cup title as well.
Anthony Kim
At 21, Kim finished runner-up in his first event on the PGA Tour. By 23, he had won twice, finished sixth on the money list and become a star for the victorious U.S. team at the 2008 Ryder Cup (left). But injuries and perhaps a little too much celebrating has stalled a career that once seemed destined for greatness.
Dustin Johnson
Johnson has won at least once in each of his first seven years on the PGA Tour, something last done by Tiger Woods. Unfortunately for DJ, his most memorable moments involve crushing losses in majorsincluding at the 2010 PGA Championship, where he was penalized on the 72nd hole (left) for unknowingly grounding a club in one of Whistling Straits' countless bunkers. Perhaps the most talented player on this list, it seems pretty safe to say he'll have a few more cracks in golf's biggest events.
Nick Watney
Watney, like Johnson, seemed poised to break out from this pack at the 2010 PGA Championship (left). But after entering the final round with a three-shot lead, an 81 dropped him to T-18. Watney bounced back with two big wins (the WGC-Cadillac and the AT&T National) in 2011 to stir talk that he could be the guy to carry the hopes of the Red, White and Blue in golf's next era, but he has won just once on the PGA Tour since.
Bubba Watson
A late bloomer, Watson didn't win on the PGA Tour until his 184th start at the 2010 Travelers Championship -- seven years after turning pro. But after a playoff loss at the PGA Championship later that year and an early 2011 win at Torrey Pines (left), the big-hitting lefty climbed to the top of everyone's list of American golf's next big stars. He certainly lived up to that billing with his thrilling win at the 2012 Mastersand added another green jacket in 2014. Watson is the current great American and at 35, still has plenty of time to add to his impressive resume.
Hunter Mahan
Mahan seemed poised for big things upon turning pro after an amateur career that included a U.S. Junior title, a runner-up at the U.S. Amateur and the 2003 Haskins Award for outstanding collegiate golfer while at Oklahoma State. After a few successful years on tour, Mahan really emerged in 2012 with a win over Rory McIlroy in the final of the WGC-Match Play and another victory at the Shell Houston Open, which propelled him to No. 4 in the world. To be considered truly great, though, Mahan needs to start winning majors.
Ryan Moore
Moore etched his name into amateur golf lore with his 2004 summer in which he won the U.S. Amateur (left), the U.S. Pub Links, the Western Amateur, as well as the NCAA Championship. Upon turning pro in 2005, he became the first player to earn his PGA Tour card through sponsor's exemptions since Tiger Woods. While he's had a solid career since with three wins, he hasn't lived up to the lofty expectations with which he arrived. Moore has yet to finish any season in the top 25 on the money list.
Keegan Bradley
Bradley's leap into this conversation came as a surprise, but that's what happens when a golfer comes from Vermont and plays college golf at St. John's. After becoming a legit contender for this imaginary title with his stunning win at the 2011 PGA Championship (his first major as a pro), Bradley has continued to play at a high level.
Rickie Fowler
Despite being one of the youngest players on this list (he's still only 25), Fowler is arguably the most popular. His style, attitude and looks have made him one of the game's stars, even if his on-course results haven't quite kept up the pace. He only has one career PGA Tour win, but recent strong performances in majors indicate his game is headed in the right direction.
Webb Simpson
2011 was Simpson's breakout year (two wins, three seconds), but his victory at the 2012 U.S. Open immediately elevated him to another level of expectations. The 26-year-old combines old-school style (sweet cardigan) and new-school technology (a belly putter he's used since his college days at Wake Forest). He may very well wind up being the steadiest of this bunch.
Patrick Cantlay
Athletes often get criticized for turning pro too early. Not this guy. After two season at UCLA, Cantlay made his pro debut at the 2012 Travelers Championship, one year after firing a second-round 60 as an amateur in the same tournament. In eight PGA Tour events as an amateur, Cantlay made seven cuts and picked up four top 25s. Unfortunately, back problems have slowed his progress, but when healthy, expect a lot more from him.
Peter Uihlein
After winning the Ben Hogan Award as the nation's top golfer as a junior at Oklahoma State in spring 2011, Uihlein turned pro that December, but took a less common route to becoming a star. Uihlein earned his European Tour card and won on the circuit for the first time in 2013 on his way to earning rookie-of-the-year honors. Expect to see a lot more of the former U.S. Amateur champ playing in his home country in the future.
Jordan Spieth
The only golfer not named Tiger Woods to win multiple U.S. Junior Amateur titles, Spieth turned pro after one year at the University of Texas and found quick success. In July 2013, he won the John Deere Classic to become the first teen to win on the PGA Tour in 82 years. Later that year, he was picked to be on the Presidents Cup team. Although he's still looking for win No. 2, he's been a mainstay on leader boards.
Patrick Rodgers
A standout golfer leaving Stanford early to turn pro? Where have we heard that before? Rodgers matched Tiger Woods' school record for wins (11) and even followed his idol by signing an endorsement deal with Nike. Obviously, it's way too early to evaluate the former top-ranked amateur golfer's pro career, but the future looks bright.
