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The 2014 NFL draft will be heavy on quarterback prospects ready to step into the pros and run an offense. But who are these quarterbacks?

We all know about Johnny Manziel—maybe too much actually, thanks to his Heisman Trophy season and summer of off-field antics. But what do we know about his game? And aside from Manziel and perceived top quarterback Teddy Bridgewater, who are the other top players at the game's most important position?

There are seniors, juniors and even redshirt sophomores who have caught the attention of the NFL this fall. Six of those quarterbacks carry a first-round grade as the college season comes to a close.

Let's learn who they are.

Teddy Bridgewater, Louisville

Junior | 6'3", 210 lbs | No. 1 overall prospect

Strengths: Bridgewater has all the tools you want from a quarterback prospect in today's NFL. He has exceptional field vision and a calm in the pocket that allows him to survey the field and find receivers in coverage.

Bridgewater can be a runner, but that's not all there is to his game. Unlike so many young quarterbacks, Bridgewater will use his mobility to set up passing lanes and evade a pass rush. He doesn't panic under pressure and forget his mechanics, either. His ability to put the ball on a line to an area where only his receiver can make a play on the ball is exceptional.

Feeling and reading the blitz is a strength of Bridgewater's, too. He does a great job recognizing coverages and pressures pre-snap, but he's also athletic enough to reverse out or scramble if a delayed blitz comes through.

It's also important to note that the Louisville offense won't put many players into the NFL. Bridgewater is doing more with less. There is not a more NFL-ready quarterback in college right now.

Weaknesses: The first thing you notice about Bridgewater is his lean frame. Ideally, he would put on weight before taking a snap in the NFL, but that is something he's improved in since arriving at Louisville. He'll continue to get bigger.

If we're being very picky, his deep ball isn't as strong, as accurate or as fiery as other big-armed quarterbacks. Bridgewater's arm is plenty strong enough, but it's definitely not as big as that of other prospects.

Comparison: Aaron Rodgers, Green Bay Packers

Best NFL fit: Jacksonville Jaguars, Tampa Bay Buccaneers, Minnesota Vikings

Marcus Mariota, Oregon

Redshirt Sophomore | 6'4", 214 lbs | No. 2 overall prospect

Strengths: The ideal dual-threat quarterback, Mariota has the arm and legs to take the NFL by storm. He's blessed with a quick-strike arm, field vision and the mobility to evade the rush, scramble or work as a runner from the backfield.

Mariota is also very good at keeping the ball out of the hands of the defense. He doesn't throw into traffic, instead showing poise and patience in working through his reads to the open man. And if no one is open, he can tuck the ball and run with equal ability.

In terms of accuracy and arm strength, Mariota is on point. The Oregon offense does allow him to throw to open receivers often, but those passes are on the mark—and that's important no matter the style of offense you're in. As for arm strength, the Ducks offense allows Mariota to throw deep and asks him to throw with velocity underneath. While he lacks a Colin Kaepernick-like fastball, his arm is plenty strong enough.

Weaknesses: At just barely 20 years old, Mariota is light on experience. When the season ends he'll have started 26 games in his college career, and that's something NFL scouts and general managers can be concerned about at times. There will also be questions about how well the Oregon offense translates to the NFL, but the success of Nick Foles in Philadelphia may quiet those critics.

From a physical and mental standpoint, there are no glaring weaknesses. Mariota will be tasked with proving he's experienced enough and that his college system isn't a gimmick.

Comparison: Colin Kaepernick, San Francisco 49ers

Best NFL fit: Jacksonville Jaguars, Minnesota Vikings, Philadelphia Eagles

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Tajh Boyd, Clemson

Redshirt Senior | 6'1", 225 lbs | No. 14 overall prospect

Strengths: Boyd plays in a pro-style offense at Clemson, and there he's enjoyed success without a ton of talent around him. The wide receivers have been talented, but the offensive line during Boyd's tenure hasn't been a strength. That's allowed him to show off his legs, his patience in the pocket and his feel for pressure. Boyd has the arm strength to sling the ball downfield, but he also shows nice touch on underneath routes and when asked to rock a timing route through traffic.

Weaknesses: Boyd lacks prototypical NFL size at 6'1", and that might be a generous listing. He'll also need to prove that his intermediate and outside-the-hashes accuracy is on point. Boyd has played the last two seasons with top-tier wide receivers DeAndre Hopkins and Sammy Watkins, and that may hurt how NFL teams view his ability. Is Boyd responsible for Clemson's offensive production, or are his playmakers?

Comparison: Jake Locker, Tennessee Titans

Best NFL fit: Minnesota Vikings, Houston Texans, Tennessee Titans, Cleveland Browns

Johnny Manziel, Texas A&M

Redshirt Sophomore | 6'0", 210 lbs | No. 16 overall prospect

Strengths: Turn on any Texas A&M game and pretend that you know nothing about Manziel—just watch what he does on the field. If you can get past the prejudices, you'll see an instinctive, athletic, smart quarterback in the Aggie offense.

Manziel is asked to make quick reads in the A&M offense, and he does so with limited mistakes in the running and passing games. He's an athletic wonder who can do things with his legs, feet and arm that few can.

And let's talk about accuracy: Manziel has improved in this area exponentially since last season. His ball placement and reads to get the ball to the open man are among the best in the nation.

Weaknesses: We know—or think we know—all about the off-field issues with Manziel: underage drinking, the alleged autograph scandal and his issues at the Manning Passing Academy.

Those perceived red flags may not bother NFL teams, though, especially given how well Manziel has played this season. The real red flags are his size and style of play. Manziel compares in size to Russell Wilson, but his style of play makes him susceptible to hits that Wilson avoids in the pocket.

Mechanically, Manziel has some bad habits. He too often throws flat-footed without stepping into passes and can hesitate midway through his throwing motion at times. Those are fixable issues, though.

No matter how big he measures, there will be those who see him running around in the backfield and think he'll never translate to the NFL. That may be the case in some offenses, and for some teams Manziel will be off limits.

Comparison: Robert Griffin III, Washington

Best NFL fit: Philadelphia Eagles, Tampa Bay Buccaneers, St. Louis Rams

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Derek Carr, Fresno State

Redshirt Senior | 6'3", 215 lbs | No. 17 overall prospect

Strengths: Mature, experienced and highly productive, Carr could ultimately be the top senior quarterback in the class. He fits the prototypical mold of what NFL teams want at the position—tall, thickly built and square-jawed.

Carr's arm is his best asset, though. With a quick trigger and enough velocity to drive the ball all over the field, he possesses the type of passing game that scouts fall in love with quickly. Not only does he have the arm, but his mobility and athleticism are quality traits. He's mobile in and out of the pocket and isn't afraid of contact.

Weaknesses: Carr's biggest obstacle to overcome may be his last name. Brother of former No. 1 overall pick David, the younger Carr will undoubtedly have to convince NFL decision-makers that he'll be a better pro than his brother was.

The biggest weakness a scout will see in Carr's game is his penchant for struggling under pressure. He'll miss a pre-snap blitz key too often and can put the offense in trouble with his missed reads. Mechanically, you want to see him step through passes more and not rely on back-foot throws as much.

Comparison: Jay Cutler, Chicago Bears

Best NFL fit: Cleveland Browns, Houston Texans, Minnesota Vikings, Arizona Cardinals

Zach Mettenberger, LSU

Redshirt Senior | 6'5", 235 lbs | No. 32 overall prospect

Strengths: No quarterback has improved as much from 2012 to now as Mettenberger. Now working under offensive coordinator Cam Cameron, Mettenberger has seen his accuracy, decision-making and awareness all jump way up the board.

The LSU senior looks like a player out of central casting. He's tall and strong and has the big arm to back it up. Mettenberger excels with any throw you ask him to make thanks to the strength, velocity and timing to do it all on the field.

His upside is perhaps the biggest advantage to his game. Mettenberger is still quite raw as a quarterback, and if his improvement in Cameron's system is any indication, he's poised to improve by leaps and bounds in the NFL.

Weaknesses: Is Mettenberger improved, or is he the product of Cameron's system? That's a big question for him to answer in film rooms across the country.

While Mettenberger has the size, the arm and the upside, he doesn't have great accuracy at times and still throws too many interceptions. He's a rhythm passer who can go through streaks of brilliance before coming back down and going through a bad streak. Finding his level will be a key for scouts, especially those who saw him dominate early in the year but maybe missed his late-season struggles.

A good quarterback coach will slightly alter Mettenberger's wide throwing mechanics, but like Philip Rivers, that may end up being a minor issue that teams aren't looking to change.

Comparison: Philip Rivers, San Diego Chargers

Best NFL fit: Arizona Cardinals, Cleveland Browns, Minnesota Vikings, Tennessee Titans