Establishing a preseason Heisman Trophy pecking order can be a tricky proposition. In fact, over the last few years, the chase for the most prestigious award in sports has been inherently unpredictable, with under-the-radar players rising up to buck the status quo.

Take Texas A&M’s Johnny Manziel, for example. He rose from relative anonymity (and a preseason quarterback competition) in 2012 to become the first freshman to win the Heisman in the award’s 78-year history. He bolstered his résumé week by week, eventually exploding onto the scene with his dismantling of Alabama in Tuscaloosa.

College football preseason archive: Check out all of SI's 2013 preview content

That’s not to say Manziel didn’t receive some help along the way. From USC’s Matt Barkley to Kansas State’s Collin Klein, players deemed ahead of Manziel repeatedly fell to the wayside as Johnny Football racked up yards, touchdowns and wins. Notre Dame linebacker Manti Te’o ultimately emerged as his biggest challenger, but Te’o came in second, the highest-ever finish for a purely defensive player.

Perhaps more than anything, last season demonstrated just how significantly the Heisman landscape has changed. Since its inception in 1935, the trophy has traditionally gone to an upperclassman. Seventy-four of the Heisman’s 78 winners have been junior or seniors. But all four underclassmen victories have occurred since 2007 (Tim Tebow, Sam Bradford, Mark Ingram and Manziel). More barriers seem poised to fall over the next several years.

So which players truly stand the best chance of hoisting the award this December? Here are the top candidates, broken into four distinct groups:

Group 1: The preseason golden boys

•Braxton Miller, QB, Ohio State

• AJ McCarron, QB, Alabama

• Marcus Mariota, QB, Oregon

• Aaron Murray, QB, Georgia

• Tajh Boyd, QB, Clemson

Not exactly the names you were expecting? Well, these five passers all have plenty of factors working in their favor. Not only are they all highly touted quarterbacks on preseason top-10 teams, but they also lead potent attacks with lots of returning talent; Oregon, Clemson and Georgia, in particular, each averaged more than 465 yards of total offense per game last fall. Given the ever-shifting dynamic of the Heisman race, they also seem to have recent history on their side: Eleven of the past 12 winners have been quarterbacks, with Alabama tailback Ingram (2009) serving as the lone exception.

Moreover, Boyd, Mariota, McCarron, Murray and Miller all lead teams that are expected to remain in the thick of the BCS hunt. While advanced stats are slowly creeping their way into college football, team success remains an important a factor in the Heisman chase. These five programs should garner plenty of headlines in 2013.

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Perhaps most important, all five quarterbacks have the ability to put up monster numbers. Miller, arguably the overall Heisman favorite, tallied 28 total touchdowns last fall. McCarron, who won the last two national championships with Alabama, led the nation in passing efficiency with an absurd 30-to-3 touchdown-to-interception ratio. Boyd set a Clemson single-season record with 37 touchdown passes, while Mariota’s 32 passing scores set a Pac-12 freshman record. Murray threw for 3,893 yards in 2012, including 427 and five scores against Nebraska in the Capital One Bowl.

The path to the New York will be challenging -- Murray and Boyd, for example, play each other in Week 1 – but it's also manageable. If these candidates' respective teams make BCS runs, they appear to have fewest number of road blocks standing in their way.

Group 2: Frontrunners with question marks

• Johnny Manziel, QB, Texas A&M

• Jadeveon Clowney, DE, South Carolina

• Teddy Bridgewater, QB, Louisville

• Marqise Lee, WR, USC

• Jordan Lynch, QB, Northern Illinois

This group features arguably the three biggest names in the 2013 hunt (Manziel, Clowney and Bridgewater), so from a hype standpoint, these players seem well positioned to make Heisman pushes. But unlike the guys in the first group, these five players each have major questions that could hinder their respective candidacies.

Manziel faces the most notable obstacle in his quest to repeat as a Heisman winner: He’s currently the subject of an NCAA investigation into whether he accepted payments for autographs, a case that puts his eligibility in jeopardy. For all of the fan and media attention paid to his offseason antics, this situation holds actual football implications, and there’s no way Manziel can join Ohio State’s Archie Griffin as a two-time Heisman winner if he can’t take the field. Manziel reportedly met with NCAA investigators for nearly six hours over the weekend, though the exact timetable for a ruling remains unclear. Even if he does play, there’s also the matter of expectations. At this point last season, most casual fans had never heard of Manziel. Now, expectations may be unrealistically high.

Staff: Johnny Manziel, Jadeveon Clowney on SI.com's Preseason All-America Team

Aside from Manziel, perhaps no other player generated more offseason headlines than Clowney. The Gamecocks’ defensive end turned in a terrific sophomore campaign, punctuated by his now-legendary hit on Michigan’s Vincent Smith in the Outback Bowl. But defensive players are at a disadvantage from the get-go. Only one player from that side of the ball, Michigan cornerback Charles Woodson (’97), has ever won the Heisman, and Woodson wasn't a purely defensive player. Clowney finished sixth in voting last season, but for him to improve, he’ll likely need an otherworldy statistical season. Given all the double teams he’s sure to face, topping his 2012 line (13 sacks and 23.5 tackles for loss) would require a monumental effort.

As for the rest of this group? Bridgewater won’t play a preseason Top 25 opponent all season, and even with massive production, it may be difficult for him to win over the majority of voters. Lynch, who finished seventh a year ago and plays in the MAC, falls in the same boat. Meanwhile, Lee will have to battle Heisman history -- only two wideouts (Tim Brown and Desmond Howard) have ever won the trophy -- and a more immediate concern: He’ll have to jell with a new quarterback, and USC has yet to announce whether Max Wittek or Cody Kessler will be its starter in 2013.

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Group 3: Elite running backs in the race

• T.J. Yeldon, RB Alabama

• Todd Gurley, RB Georgia

• Lache Seastrunk, RB Baylor

• De'Anthony Thomas, RB Oregon

• Duke Johnson, RB, Miami

From a purely historical perspective, this group of players has more going for it than either of the two listed above. Forty-one trophies have been doled out to running backs, the most of any position. While tailbacks have met limited success recently (before Ingram, the last back to win the Heisman was Wisconsin’s Ron Dayne in 1999), each rusher on this list can make a case for New York this season.

The two favorites here likely hail from the SEC. Alabama’s Yeldon is coming off a freshman campaign in which he rushed for 1,108 yards and 12 touchdowns -- and he wasn’t even the Crimson Tide's starter. With Eddie Lacy off to the NFL, Yeldon is poised to be the feature back this year, and that could mean huge numbers. Over in Athens, Georgia’s Gurley raced for 1,385 yards to lead SEC backs in rushing as true freshman. Even with fellow back Keith Marshall in the fold, he has the talent to improve on that production, but he’ll have to outshine the other candidate on his team (Murray) to really make a push for the trophy.

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That’s the primary question facing Oregon’s Thomas as well. The all-purpose speedster will finally get his shot as the Ducks’ primary back, but Mariota has garnered much of the early Heisman chatter in Eugene. Meanwhile, Seastrunk and Johnson have the potential to put up eye-popping stats, but their team success remains a wild card. Both Baylor and Miami have suspect defenses, and voters have typically been hesitant to get behind candidates on middle-of-the-pack contenders.

With a wealth of quarterbacks squarely in the spotlight, it might take some extraordinary measures for a running back to emerge as the favorite. Still, the guys listed here may have the talent to make that happen.

Group 4: The dark horse candidates

• Jameis Winston, QB Florida State

• Brett Hundley, QB UCLA

• David Ash, QB Texas

• Devin Gardner, QB, Michigan

• Trevor Knight, QB Oklahoma

If it wasn’t made clear already, Manziel’s out-of-nowhere Heisman campaign tossed many of the award’s historical limitations out the window. Though each member of this group (except Knight) is better known now than Manziel was at this juncture last year, none is expected to make a strong run at the Heisman. After Manziel’s venture to New York, however, it seems foolish to completely count them out.

These five quarterbacks each hold the reins to teams that could contend in their respective conferences, even though they might not be considered preseason favorites. That could give each player the type of surprise spotlight necessary to generate dark-horse Heisman discussion. Even though he’s yet to complete a college pass, Winston has already fielded plenty of hype dating back to spring practice, and the ingredients for a Heisman run are in place. The dual-threat redshirt freshman takes over for E.J. Manuel and will lead a top-15 team with plenty of returning offensive weapons.

Blake Bell