Sports on Earth is counting down the best returning players at every position in college football heading into the 2016 season. Last week, we broke down the top 20 defensive ends and top 20 defensive tackles. This week, the series finishes with the top 30 quarterbacks.

There is little doubt who belongs at the top of the list of best quarterbacks returning to college football in 2016, but it doesn't take long for the exercise to get a bit difficult. The SEC in particular has gone through an unexpected dip in proven talent, and several high-profile teams nationally -- Florida State, Alabama, USC, Michigan, Stanford, TCU and more -- are still trying to pick a starter entering the fall.

Our preseason list thus sticks mostly to known quantities. Players like Florida State's Deondre Francois, North Carolina's Mitch Trubisky, USC's Max Browne and whomever Alabama chooses to start could easily join this list by the end of the season. For now, though, they are all relative unknowns as starting quarterbacks (Francois, Brown and many other promising QBs still have to actually win their jobs). This list is significantly weighted in favor of those with starting experience, creating room for the plethora of proven and productive Group of Five quarterbacks returning.

This list will undoubtedly look a lot different by midseason, at least beyond the top handful of players, and the following rankings are based on what players have accomplished and what kind of impact they are capable of making at the college level, not necessarily NFL draft projections. Teams are also listed only once, so multiple players are listed for competitions featuring multiple players with starting experience.

2016 player rankings: Running Backs |Linebackers | Wide Receivers/Tight Ends | Defensive Backs | Offensive Linemen | Defensive Linemen | Quarterbacks

30. Tommy Armstrong, Nebraska. Without including first-year starters, this range in the rankings is wide-open, with a bunch of candidates who show flashes of brilliance but are inconsistent and flawed (we could easily swap Armstrong for Minnesota's Mitch Leidner, for example). Armstrong has started 33 games in his career. He can be successful as a downfield passer, and he's a talented runner. He also has accuracy issues and has thrown 28 interceptions over the last two seasons. Armstrong's improvement will play a big role in Nebraska trying to turn things around after Mike Riley's 6-7 debut, with Riley attempting to adapt to the quarterback he inherited and Armstrong attempting to adapt to a system that isn't a perfect fit for his skill set. Armstrong was at his best in the Foster Farms Bowl, when he completed 12 of 19 passes for 174 yards and a TD with no picks and ran 10 times for 76 yards and a TD. He needs help around him, like he got in that game, to avoid putting too much pressure on his decision-making as a passer. Overall as a junior, he threw for 3,030 yards, 22 TDs and 16 INTs and ran for 400 yards and seven TDs.

29. Dakota Prukop, Oregon. Prukop is both a known quantity and one of college football's greatest unknowns. At Montana State, he threw for 3,025 yards, 28 TDs and 10 INTs while rushing for 797 yards and 11 TDs against FCS/Big Sky Conference competition. Now, he'll follow in the footsteps of Vernon Adams as a graduate transfer moving up to Oregon. Adams led the nation in passer rating despite injury issues. Prukop is more of a runner than Adams, and he has had more time to learn the system, as he enrolled over the winter. It's possible he'll be another solid answer for Oregon in the post-Mariota era, but first he has to beat out redshirt freshman Travis Jonsen to win the job.

28. Justin Thomas, Georgia Tech. The question is which Thomas will be running the show for Georgia Tech this year. Last year, Thomas ran for 488 yards and six TDs and completed 41.7 percent of his passes for 1,345 yards and 13 TDs as the Yellow Jackets plummeted to 3-9. The year before, as a sophomore, Thomas ran for 1,086 yards and eight TDs and completed 51.3 percent of his passes for 1,719 yards and 18 TDs as the Yellow Jackets won the ACC Coastal and the Orange Bowl. At times, he has been an expert point guard for this option attack, and Georgia Tech needs a bounce-back season from its quarterback this fall to snap out of its unexpected funk.

27. Anu Solomon, Arizona. Injuries have unfortunately limited Solomon and were partially responsible for a slight downturn as a sophomore. As a freshman, he helped lead the Wildcats to the Pac-12 South title, but last year he missed two full games and ran for just 198 yards. In the passing game, he was up and down, ultimately completing 62.1 percent for 2,667 yards with 20 TDs and five INTs. There's no question that Solomon is a talented player, and in Rich Rodriguez's offense, the potential is there for him to take the next step and become an All-Pac-12 caliber yet. First, however, he has to alleviate durability concerns and solidify his standing atop the depth chart with sophomore Brandon Dawkins pushing him.

26. Dane Evans, Tulsa. Evans became one of college football's most prolific passers with former Baylor offensive coordinator Philip Montgomery calling the shots. The 6-foot-1, 218-pound senior completed 62.9 percent of his passes for 4,332 yards with 25 TDs and eight picks, including 427 yards and four TDs against Oklahoma and 374 yards and three TDs against Virginia Tech. Evans was at his best in two matchups against Power Five teams in games in which the Golden Hurricane scored a total of 90 points in losses. With a stellar receiving corps and a year of experience in the system, he's in line for huge numbers again this season.

25. Zach Terrell, Western Michigan. A steady presence for an improving offense, Terrell has been the full-time starter the last two years as Western Michigan has risen to an eight-win team under P.J. Fleck. Hopes are higher this year, with Terrell leading a loaded offense that also has a potential All-American wide receiver in Corey Davis. As a junior, Terrell completed 67 percent for 3,526 yards, 29 TDs and nine INTs, for an offense that ranked 11th in yards per play. Terrell finished seventh in the nation in passer rating.

24. Cooper Rush, Central Michigan. A second-team All-MAC pick as a junior, Rush has led the Chippewas to back-to-back 7-6 bowl seasons and hopes to push them a step, with the hope that they'll be a factor in the MAC West race again after finishing in a four-way tie at 6-2 last year. He has a shot to break MAC great Dan LeFevour's school passing record this year, after completing 66.3 percent for 3,848 yards with 25 TDs and 11 INTs in 2015. The 6-foot-3, 227-pound senior now enters his fourth season as starter, and while he doesn't bring much running ability to the table, it's possible he could be a mid-to-late-round NFL draft pick because of his pure passing ability.

23. Brent Stockstill, Middle Tennessee. The son of Blue Raiders coach Rick Stockstill ousted incumbent Austin Grammar as a redshirt freshman and proved his father's decision right. Stockstill shined, completing 66.7 percent for 4,005 yards with 30 TDs and nine INTs, making him one of the most productive freshmen in the country. He's in a fantastic situation to continue to succeed, with MTSU potentially in the conference title mix. Tony Franklin -- who coached Jared Goff at Cal -- steps in as offensive coordinator, sophomore receiver Richie James is back after catching 108 passes and the Blue Raiders brought in Ole Miss transfer I'Tavius Mathers at running back.

22. Quinton Flowers, South Florida. At last, Willie Taggart has his quarterback. After a pair of ugly seasons for the Bulls on offense, Taggart turned to Flowers, and he showed big potential as a sophomore in leading USF to an 8-5 record. Flowers threw for 2,290 yards, 22 TDs and eight INTs and ran for 991 yards and 12 TDs, proving to be a dangerous dual-threat. With the combination of Flowers and RB Marlon Mack returning, the Bulls are a contender in the American and have a chance to pull the upset and dethrone Houston.

21. Gunner Kiel, Cincinnati. From verbal commitments to Indiana and LSU, to enrolling at and transferring from Notre Dame, to an up-and-down stint at Cincinnati, Kiel has had an adventurous career as a five-star recruit. Now, Kiel is attempting to regain his starting job after leaving the team for personal reasons last December and missing the Bearcats' bowl trip. Last year, Kiel played in 10 games, completing 65.2 percent for 2,777 yards with 19 TDs and 11 INTs. He missed time in the middle of the year with a head injury, and Hayden Moore -- then a freshman -- stepped in and showed a lot of potential while dealing with turnover problems. Moore played in nine games, completing 59.1 percent for 1,885 yards with nine TDs and 11 picks. Kiel also missed a lot of the spring with injury issues, and coach Tommy Tuberville has declared the competition open. Should Kiel return to the No. 1 job, he'll be playing with an entirely new receiving corps, plus a new offensive coordinator after Eddie Gran left for Kentucky.

20. Davis Webb, California. The future appeared to be bright for Webb at Texas Tech, but injury problems derailed his career, and he ultimately ceded the starting job to Patrick Mahomes. A graduate transfer, Webb initially committed to Colorado, only to change course and opt for Cal, where he'll likely be the replacement for No. 1 overall pick Jared Goff in Sonny Dykes' wide-open offense. The 6-foot-5 senior has a lot of tools and still has NFL potential. At Cal, he should easily adapt to Dykes' offense after playing under Kliff Kingsbury. He started 14 games and played in 23 while in Lubbock, throwing for 5,557 yards, 46 TDs and 22 INTs with a 61.4 percent completion rate.

19. Nick Mullens, Southern Miss. Southern Miss has returned to respectability, with Mullens leading a resurgence after a few shockingly aimless seasons in Hattiesburg. Unfortunately, Mullens will move forward as a senior without head coach Todd Monken, now the Tampa Bay Buccaneers' offensive coordinator, but he's well-positioned for a great final season under new coach Jay Hopson, formerly of Alcorn State. Last year, the Eagles improved from 3-9 to 9-5 and scored 40 points per game. Mullens shined, completing 63.5 percent for 4,476 yards, 38 TDs and 12 INTs in 14 games, including 331 yards against an excellent Washington defense in the Heart of Dallas Bowl and 447 yards at Nebraska. Despite the loss of a head coach, Mullens will have Southern Miss right back in the thick of the Conference USA title race.

18. Brett Rypien, Boise State. Perhaps the biggest recruit in Boise State history, Rypien jumped to the starting job as a true freshman after Ryan Finley suffered a season-ending injury in the Broncos' third game. Rypien didn't disappoint. While he had a few rough games -- see the turnover-plagued losses to Utah State and New Mexico -- he earned first-team All-Mountain West honors by completing 63.6 percent for 3,350 yards with 20 TDs and eight picks. The nephew of former NFL QB Mark Rypien, Brett Rypien is a great building block for Boise State to continue pursuing major bowl bids under coach Bryan Harsin, and with more experience behind him, he'll likely start limiting his mistakes.

17. Taysom Hill and Tanner Mangum, BYU. The Cougars' quarterback battle offers two drastically different options. Hill has seemingly been in Provo forever, with injuries derailing a promising career for the talented dual-threat. A 6-foot-2, 230-pound senior who is 25 years old, Hill ran for 1,344 yards (humiliating Texas in the process) and passed for 2,938 yards in 2013, but he has played in a total of eight games since then. Last year, he injured his foot in Week 1 -- an injury that ended his season -- which opened the door for Mangum, a 22-year-old freshman who was a touted passer out of high school. Mangum engineered miracle wins against Nebraska and Boise State and ultimately threw for 3,377 yards with 23 TDs and 10 INTs. Now, a new coaching staff, including new offensive coordinator Ty Detmer, has a tough decision to make with two great options in Hill, who has been such a big part of the program for years, and Mangum, who is the team's future and played well as the starter last year.

16. C.J. Beathard, Iowa. After winning the starting job from Jake Rudock, Beathard propelled Iowa to unexpected heights last season, directing an undefeated regular season before the Hawkeyes fell just short of a Big Ten title and a playoff bid. As a junior, Beathard completed 61.6 percent for 2,809 yards with 17 TDs and five INTs and ran for 237 yards and six TDs. He was often banged up, and those injuries limited his mobility, which is otherwise a big strength because he is able to move the pocket and keep plays alive, bringing a different dimension to the Iowa offense. With a healthy Beathard returning, Iowa remains in the driver's seat in the Big Ten West.

15. Joshua Dobbs, Tennessee. Dobbs has been a solid starter for the Vols the last year and a half, bringing mobility and intelligence to the table. Now, the hope is that he can take his game to another level and help propel the Volunteers over the hump finally to an SEC East tile. Dobbs has had moments of brilliance, but his play has been up and down -- particularly in the Vols biggest games. As a junior, he completed 59.6 percent of his passes for 2,291 yards and 15 TDs. While he threw only five interceptions, he also averaged only 6.7 yards per attempt and finished eighth in the SEC in passer rating. However, his rushing ability boosts his value, as he ran for 671 yards and 11 TDs. With more experience around him, big things are expected in 2016.

14. Greg Ward Jr., Houston. As Ohio State's offensive coordinator Tom Herman successfully moved from Braxton Miller to J.T. Barrett to Cardale Jones in helping to lead the Buckeyes to a national championship. At Houston, he succeeded wildly in his first season, becoming the hottest rising name in coaching. It helped that he inherited a quarterback in Ward who proved to be a perfect match for his system. As a junior, Ward completed 67.2 percent for 2,828 yards, 17 TDs and eight picks and ran 198 times for 1,108 yards and 21 TDs, leading the Cougars to a 13-1 record, an AAC title and a win over Florida State in the Peach Bowl. An elusive and explosive runner who limited his mistakes as a passer last season, Ward joins Herman as the biggest reasons the Cougars will open the season around the preseason top 15, as the favorites to earn the Group of Five's major bowl bid again.

13. Jake Browning, Washington. While the recipient of substantially less hype than fellow Pac-12 freshman staring QB Josh Rosen of UCLA, Browning actually finished ahead of Rosen in passer rating, completing 63.1 percent for 2,955 yards with 16 TDs and 10 INTs. At the center of a young offense, Browning experienced plenty of growing pains -- it didn't help that top deep threat John Ross missed the season -- but he got better as the season went on. With a more experienced supporting cast, the return off Ross and now a full year as starter behind him, Browning -- a top-100 overall recruit who put up absurd passing numbers in college in California -- is poised for a breakout season as Washington pushes for a breakthrough of its own as a team on the rise with legitimate Pac-12 championship aspirations.

12. Mason Rudolph, Oklahoma State. With running threat J.W. Walsh gone, the Oklahoma State offense belongs solely to Rudolph now. A four-star recruit, Rudolph played well when pressed into duty as a true freshman late in the 2014 season, and last year he was the primary passer for a quick-hitting offense that made a lot of big plays, hitting 62.3 percent of his attempts for 3,770 yards, 21 TDs and nine INTs. Rudolph is up to 6-foot-5, 235 pounds, and after a stellar sophomore campaign, he's hoping for a breakthrough season that could move him into first-round NFL draft consideration. A big, strong-armed pocket passer, Rudolph will especially be helped if a problematic offensive line takes a step forward.

11. Lamar Jackson, Louisville. While his passing accuracy needs work, Jackson ended the 2015 season in dazzling fashion because of his dynamic running ability. In wins over Kentucky and Texas A&M, the true freshman completed just 20 of 47 passes over two games. But he ran for 186 yards and two TDs to beat the rival Wildcats, then ran for 226 yards and two TDs to beat the Aggies in the Music City Bowl. Despite starting only seven games behind an inconsistent offensive line, Jackson finished his debut season with 960 rushing yards, while completing 135 of 247 passes for 1,840 yards, 12 TDs and eight INTs. He undoubtedly has a lot of room to grow as a passer, but he has a good quarterback tutor in Bobby Petrino, and his explosive running already makes him a great candidate for a breakout season after a breakout bowl game.

10. DeShone Kizer and Malik Zaire, Notre Dame. Starting quarterback decisions don't get much harder than the one coach Brian Kelly faces this preseason. Even the best quarterback battle can still cause problems -- see Ohio State last year -- but the Fighting Irish are in great shape regardless of who starts. Zaire, with a strong arm and excellent ability outside the pocket, supplanted Everett Golson last year, only to break his ankle against Virginia in Week 2. He was replaced by Kizer, a redshirt freshman who plays within the pocket more but is also an excellent runner. Upon replacing Zaire, threw for 2,880 yards and 21 TDs and ran for 520 yards and 10 TDs. Now, it's up to Zaire to earn his job back, which is not an easy task.

9. Patrick Mahomes, Texas Tech. The son of former Major League pitcher Pat Mahomes, the latest prolific Texas Tech passer has become an exceptional fit for Kliff Kingsbury's offense. The 6-foot-3, 219-pound junior can stand in the pocket and deliver strikes downfield, but he also fits Kingsbury's version of the Air Raid that lets the quarterback run. In his first full year as starter, Mahomes completed 63.5 percent for 4,653 yards with 36 TDs and 15 INTs and ran 131 times for 456 yards and 10 TDs. While he's still working on decision-making and becoming more accurate, Mahomes is a talented passer who is capable of moving the pocket, throwing on the run and improvising with impressive escapability. He had 21 completions of 40 yards or more and could make a push for 5,000 passing yards this season as a junior.

8. Seth Russell, Baylor. Prior to a season-ending neck injury, Russell led the nation in passer rating in his first season as starter, beating up on Baylor's lighter first-half schedule to complete 59.5 percent of his attempts for 2,104 yards (10.5 per attempt), 29 TDs and six interceptions in seven games, despite barely playing in some second halves of blowouts. He also brought underappreciated running ability to the table, with 402 yards and six TDs. There is a lot up in the air with Baylor now, as it moves forward under acting coach Jim Grobe and needs to replace four starting offensive linemen and two of its top three receivers, Corey Coleman and Jay Lee. And things may get more complicated with reports that touted sophomore QB Jarrett Stidham, who was set to compete with Russell, may transfer. This offense should still be prolific, and Russell showed off a tremendous skill set when healthy last year, with a deadly combination of running and downfield passing, so it will still be in good hands if Russell is ready to go.

7. Brad Kaaya, Miami. After a solid two seasons as starter, Kaaya now hopes to take his game to another level under new coach Mark Richt, as the recipient of early hype as a possible top-10 NFL draft pick. The tools are there: The 6-foot-4, 210-poud Kaaya won the job as a freshman and has had to pilot the Canes through a pair of relatively tumultuous seasons, without a lot of help from his offensive lineman. But he's a strong-armed, poised pocket passer who keeps his eyes downfield with pressure around him. His mechanics are a work in progress -- especially his lower body -- and he's not mobile, but he has avoided mistakes the last season and a half, with only 12 interceptions in 19 games. As a sophomore, he completed 61.2 percent for 3,238 yards, 16 TDs and five picks. With another year of experience under his belt and a strong coaching hire in Richt, plus a more seasoned line, Kaaya stands a good chance of taking that next step and cashing in at the pro level.

6. Luke Falk, Washington State. Falk is poised to take a shot at 5,000 passing yards in a season as Mike Leach's latest incredibly productive, high-volume passer. The junior attempted 53.7 passes per game last season -- nearly 10 more than anyone else -- and ranked second in completion percentage (69.4), throwing for 4,561 yards, 38 TDs and eight INTs in 12 games. The Cougars rarely ran the ball, with Falk expertly executing Leach's Air Raid offense. For his numbers to take another step, Falk will have to throw the ball downfield a bit more, as he averaged a modest 7.1 yards per attempt and ranked 44th in completions of 30 yards or more, according to cfbstats.com. Still, he's an accurate and smart distributor who has earned Leach's trust, and with nearly his entire receiving corps back, Falk could end up having one of the most prolific seasons, in terms of pure yardage, in college football history.

5. Chad Kelly, Ole Miss. Kelly's Ole Miss debut went better than anyone could have hoped. After an ignominious ending to his career at Clemson, then an arrest soon after announcing his transfer from junior college to Ole Miss, Kelly won the Rebels' starting job and earned second-team All-SEC recognition. The nephew of NFL great Jim Kelly, he completed 65.1 percent of his throws for 4,042 yards, 31 TDs and 13 INTs and ran for 500 yards and 10 TDs, making him a dangerous dual-threat for an up-tempo offense that beat Alabama again and finished fourth nationally in yards per play. Kelly's college career appeared ready to be a bust, but instead he reinvented himself at Ole Miss and will return for his senior season as the best quarterback in the SEC.

 

4. Josh Rosen, UCLA. There's no such thing as a flawless season for a true freshman starting quarterback, but Rosen generally handled his early responsibility well, beginning to live up to the enormous five-star hype that followed him to the Bruins. A prototypical pro prospect, the 6-foot-4, 210-pound Rosen is poised and mechanically sound, with impressive arm strength. He'll adapt to more of a pro-style offense this season with Kennedy Polamalu replacing Noel Mazzone as offensive coordinator, and it will suit him well. Last year, he completed 60 percent for 3,669 yards, 23 TDs and 11 INTs, making typical freshman mistakes but overall showing an enormous ceiling as a polished, smart passer with all the necessary tools. He should become one of the nation's best quarterbacks over the next couple seasons before he inevitably turns pro.

3. J.T. Barrett, Ohio State. Think back to Nov. 29, 2014, before the Cardale Jones-led playoff run, before the hype, madness and quarterback swapping of 2015. Think back to the rise of Ohio State behind a young, unexpected starting quarterback. Pressed into duty as a redshirt freshman after a preseason injury to Braxton Miller, Barrett took some early lumps but thrived over the course of the 2014 season, finishing fifth in the Heisman race by completing 64.6 percent of his passes for 2,834 yards, 34 TDs and 10 for INTs and rushing for 938 yards and 11 TDs. He looked like an ideal Urban Meyer quarterback, a smart and accurate passer capable of beating defenses with his feet. And then he broke his leg on that late fall Saturday against Michigan, setting the stage for over a year of Ohio State quarterback drama and an inconsistent season when he saw the field in 2015. That's all over now, though. Jones and Miller are gone, along with most of Ohio State's offense. This is Barrett's show, and after the offense's identity crisis a year ago, expect the 2016 Buckeyes to be more sure of what they want to be, even if they're younger and less seasoned overall. Barrett was a Heisman candidate two years ago, and he can return to that level.

2. Baker Mayfield, Oklahoma. Mayfield has already had one of the best careers ever for a walk-on quarterback, and now he still has two years of eligibility remaining after a change in Big 12 transfer rules. After walking on at Texas Tech and transferring to Oklahoma, Mayfield sat out a year, then ousted Trevor Knight to win the starting quarterback job. The switch paid off in a big way for the playoff-bound Sooners. Mayfield dazzled with his escapability and improvisational skills, forming a perfect partnership with new Sooners offensive coordinator Lincoln Riley. Mayfield finished fourth in the Heisman vote, completing 68.1 percent of his passes for 3,700 yards, 36 TDs and seven INTs while rushing for 405 yards and seven TDs. He's one of the most frustrating players to defend, because he's poised and accurate within the confines of a dangerous Air Raid system while also being able to be cool under pressure and operate outside the system when things break down.

1. Deshaun Watson, Clemson. It took a leap of faith to place Watson atop this list last year. Then a sophomore, he had started only five games as a freshman and saw his rookie season ended by a torn ACL. And yet it was impossible not to be enticed by Watson's arsenal of tools: sharp arm strength, poise, intelligence, speed, command of the offense at a young age. Watson delivered on his promise and then some, clearly becoming the best quarterback in the country in 2015. He led Clemson to an undefeated regular season, an ACC championship and a spot in the national championship game against Alabama, in which he delivered one of the most spectacular performances for a losing team we've ever seen, with 405 yards and four TDs passing and 73 rushing yards against an all-time great Crimson Tide defense. Watson finished third in the Heisman Trophy voting, and by the end of 15 games he ran for 1,105 yards and threw for 4,105 yards, accounting for 47 total TDs. When Watson gets into a rhythm, he appears to be playing a different game than the defense, always one or two moves ahead with his decision-making and ability to both distribute the ball to a deep roster of talented skill players and make things happen on his own as a runner. With nearly his entire offense back, plus a now-healthy Mike Williams at receiver, Watson has a chance to lead one of the best offenses in college football history this fall. Whereas last year's quarterback rankings required significant projecting, this year's require no debate: Deshaun Watson is the best quarterback in college football.

Honorable mention: Eric Dungey, Syracuse; Kevin Ellison, Georgia Southern; Drew Hare, Northern Illinois; Brandon Harris, LSU; Kenny Hill, TCU; Skyler Howard, West Virginia; Trevor Knight, Texas A&M; Taylor Lamb, Appalachian State; Mitch Leidner, Matt Linehan, Idaho; Chase Litton, Marshall; Wes Lunt, Illinois; Kent Myers, Utah State; Nathan Peterman, Pittsburgh; Thomas Sirk, Duke; Nick Stevens, Colorado State; Mitch Trubisky, North Carolina; Favian Upshaw, Georgia Southern; P.J. Walker, Temple

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Contact Matt at matt.brown5082@gmail.com and follow him on Twitter @MattBrownCFB and Facebook.

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