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Johnny Manziel looks to repeat his 2012 Heisman-winning campaign this season.The 2013 college football season has the potential to showcase one of the greatest quarterback classes ever. Eight of the top 10 teams in last year’s final AP Poll return their starting quarterbacks, and every conference except the Big 12 returns either their first- or second-team quarterbacks from last season.

In preparation for the 2013 season, ESPN Stats & Info will take a deeper look at the top QBs entering the fall. The list is built off of Phil Steele’s list of top quarterback units. On Wednesday, we look at the top returning quarterback, Heisman-winner Johnny Manziel.

A Look Back at 2012

Manziel took the CFB world by storm last season, becoming the first freshman to win the Heisman Trophy. Manziel set the SEC record for total yards in a season while accounting for more than 70 percent of the Texas A&M Aggies' total yards. He also had seven games with at least two pass and two rush touchdowns, the most by any player in one season since 2000.

Most Games with 2 Rush TD & 2 Pass TD

Single Season Since 2000

Manziel had an uncanny ability to make plays happen when things broke down. He scrambled for 857 yards and 38 first downs on 86 scramble attempts, including an FBS-high 22 first downs on third down.

In terms of passing, Manziel completed 68 percent of his passes, which ranked ninth in FBS. He put his receivers in positions to run after the catch, which is why Texas A&M ranked sixth among colleges in AQ conferences in yards after the catch.

All of these factors resulted in Manziel ranking first last season in ESPN’s new Total QBR metric, which will be unveiled for college football this fall.

What’s Ahead for 2013?

The biggest question for Manziel heading into the 2013 CFB season is whether he can repeat his performance from a year ago. Recent history has proven that some of the top freshman quarterbacks have been able to repeat their successes even after the spotlight has been shined upon them.

Since 2006, there have been four quarterbacks who ranked in the top 10 in non-clutch weighted Total QBR during their freshman seasons –- Andrew Luck, Terrelle Pryor, Sam Bradford and Colin Kaepernick. Luck and Bradford went on to lead the nation in Total QBR in their sophomore seasons, and all four players ranked in the top 12 in QBR again before leaving for the NFL.

Pryor, in particular, can be used as a model to show that players can replicate strong scrambling seasons. After scrambling for 357 yards in 2009, Pryor went on to scramble for 356 yards and average 9.9 yards per scramble in 2010.

One area in which Manziel can improve heading into next season is his downfield accuracy. He completed less than 42 percent of his passes thrown more than 15 yards downfield, which ranked 40th out of 108 qualified BCS-AQ quarterbacks.

If Manziel's sessions with “quarterback guru” George Whitfield Jr. can improve his downfield precision, a second Heisman trophy may not be far from his grasp.