For every rookie in the NFL, life is a series of discoveries. Some come from college convinced that they're going to make it big, only to have reality slap them hard upside the head. Other players rise up through the ranks, with only their faith in themselves keeping them going, and they wind up beating the odds. The 2014 rookie class has seen its own share of ups and downs. With one week left in the regular season, here are the first-year players who have impressed the most.

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Quarterback: Teddy Bridgewater, Minnesota Vikings/Derek Carr, Oakland Raiders

Carr, the 36th overall pick, may have had this spot locked up midseason -- he's done a tremendous amount with very little around him -- but it's Bridgewater who has moved ahead with a great last month. In each of his last four games, the Vikings' quarterback (selected with the last pick in Round 1) has completed over 70 percent of his passes, and while he still has issues with accuracy and ball placement, he's tremendous under pressure, and he's starting to look like the kind of quarterback who can lead a franchise to better things. Carr has certainly looked like that as well, throwing 20 touchdowns to his 11 interceptions. You'd like to see him unleash it a bit more downfield -- Carr's 5.53 yards-per-attempt is by far the lowest among qualifying NFL quarterbacks this season -- but Carr is mobile, tough, smart and whoever takes over in Oakland from coaching and personnel perspective will have something to work with in 2015.

Running Backs: Jeremy Hill, Cincinnati Bengals/Tre Mason, St. Louis Rams

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Hill now stands at 1,024 rushing yards for the season after his 22-carry, 147-yard performance against the Broncos on Monday night -- a win that put the Bengals in the playoffs for the fourth straight season. And it was Hill's 85-yard touchdown scamper with 10:09 left in the first quarter that put the team back on track after Andy Dalton's pick-six to Aqib Talib. In the Bengals' last two games, Hill has taken the ball 47 times for 295 yards. At 6-foot-1 and 238 pounds, the team's second-round pick has all the power, speed and agility you could want in a running back. As for Mason, the third-rounder who broke Bo Jackson's rushing records at Auburn has been impressive in the Rams' power running game, amassing 737 yards on 168 carries.

Receivers: Odell Beckham Jr., New York Giants/Mike Evans, Tampa Bay Buccaneers

Has any rookie been more impressive than Beckham? Despite losing the first month of the season to injury, the LSU alum and 12th overall pick has 79 receptions on 111 targets for 1,120 yards and 11 touchdowns, and he's made highlight catch after highlight catch. Over the last eight weeks of the season, Beckham leads the NFL in catches (69), yards (1,014), and only Mike Evans and Dez Bryant have more touchdowns than Beckham's eight. As for Evans, he's proven to be the member of that Texas A&M passing attack who has transcended any NFL yips, while Johnny Manziel has been left to figure it out. In a Tampa Bay offense without an actual coordinator and with an unimpressive quarterback rotation, the Bucs' first-round pick has been a beast in the red zone, and one of the league's best contested-catch receivers.

Tight End: Jace Amaro, New York Jets

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Not much has gone right with the Jets' passing offense this year, but in Amaro, the team looks to have a weapon at the tight end position with great potential. The second-round pick's highlight game this season was his 10-catch, 68-yard game against the Broncos on Oct. 12 -- since then, injuries and the general malaise surrounding the team's quarterback position have conspired to limit his opportunities. He has just three catches for 26 yards in his last five games.

Offensive Tackles: Taylor Lewan, Tennessee Titans/Greg Robinson, St. Louis Rams

Not a great season for rookie tackles. Lewan (the 11th overall pick) has been out since late November with a high-ankle sprain and has been up-and-down in overall performance, but he's allowed just 11 total pressures in 359 passing snaps, per Pro Football Focus. Robinson started his rookie campaign at left guard and worked his way outside to tackle halfway through the season. The second overall pick has allowed five sacks overall, but just one in the last four games.

Offensive Guards: Joel Bitonio, Cleveland Browns/Zack Martin, Dallas Cowboys/Trai Turner, Carolina Panthers

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On the other hand, it was a great draft class for guards. Were it not for the relative anonymity of the guard position, Bitonio might have a legitimate shot at the Offensive Rookie of the Year award. He's played every snap for the Browns this season, allowing just one sack -- and that came last Sunday against the Panthers, with a quarterback in Johnny Manziel who seems to invite pressure. Mostly a tackle at Nevada, the Browns' second-rounder seems to have the perfect athletic temperament to be an NFL guard -- aggressive and nasty, but with a focus on outstanding technique. Martin made a seamless move from left tackle at Notre Dame to right guard in the pros, and the 16th overall pick is one of the main reasons the Cowboys have the league's best overall offensive line.

I had Turner pegged as one of the more underrated linemen in the 2014 draft class -- he was projected by many as a middle-round prospect (the Panthers took him in the third round), but every time I watched his LSU tape, it seemed that there were bodies flying everywhere. He hasn't allowed a single sack in 618 snaps, which speaks to his improved pass-blocking.

Center: Corey Linsley, Green Bay Packers

The Packers didn't know what they were in for when they had to start Linsley in the season opener against the Seahawks' malevolent defense, but he allowed just one hurry in that game, and he's held his own all season, playing in each of Green Bay's 1,004 offensive snaps this season. He's given up a couple of sacks in the last month, but the fifth-rounder's progression from Ohio State's basic passing offense to Green Bay's multi-formation dance has been singularly impressive.

Defensive Tackles: Aaron Donald, St. Louis Rams/Justin Ellis, Oakland Raiders

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Donald hasn't just been the most impressive rookie at his position -- it could be argued that he's been the most impressive player at his position over the last month or so. Donald has eight sacks on the season, and five total in his last six games. Taken 13th overall by the Rams, he's an absolute wrecking ball as a three-tech tackle, requiring multiple blockers on a high percentage of plays, and his 39 total pressures is by far the highest number for any rookie tackle. In fact, it's the most total pressures for any rookie tackle since Ndamukong Suh put up 41 for the Lions in 2010. Ellis, a fourth-rounder, has been a good surprise in a Raiders draft class that has been pretty outstanding -- his 14 run stops is second behind Donald's 22 among rookie tackles.

Defensive Ends: Timmy Jernigan, Baltimore Ravens/Kony Ealy, Carolina Panthers

While there have been no 4-3 sackmaster ends in this draft class to date, Ealy has impressed at times, and he's got a sack in each of his last two games. The Panthers' second-round pick has been a rotational player (342 defensive snaps) but has put himself in position for more work in 2015. Jernigan, a fellow second-rounder, leads all rookie ends with 21 total pressures, and though he's helped a great deal in that regard by the attention opposing blockers must pay to Terrell Suggs, Elvis Dumervil and Pernell McPhee, he's been getting more reps and making an impact for the Ravens during their playoff push.

Outside Linebackers: Khalil Mack, Oakland Raiders/Anthony Barr, Minnesota Vikings

While I have Aaron Donald as my drop-dead Defensive Rookie of the Year, the voices calling for Mack to get the award wouldn't get much argument from me. The fifth overall pick has put up a whopping 51 total pressures (only Denver's Von Miller has more among all 4-3 outside linebackers this season), and he ranks third in run stops at his position with 41, behind only Tampa Bay's Lavonte David and Detroit's DeAndre Levy. Barr hasn't been quite as impactful in Mike Zimmer's defense, and a knee injury ended his season in mid-December, but his coaches and teammates have been very impressed with his development. The No. 9 overall pick has the potential to be a consistent edge-pressure player, and he's improving in coverage.

Inside Linebackers: Chris Borland, San Francisco 49ers/C.J. Mosley, Baltimore Ravens

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When the 49ers lost Patrick Willis for the season to a toe injury in November, and failed to get NaVorro Bowman back from the knee injury he suffered in the 2013 NFC Championship Game, the 49ers had to rely on Borland to pick up the slack. The rookie from Wisconsin did so admirably, amassing 107 tackles, a sack and two interceptions before his own season was cut short in mid-December with an ankle injury. More than a tackle magnet in the middle of the field, the third-round pick proved to be a very aware player who seemed to anticipate what was happening around him before it happened. Mosley (who went 17th overall) has had the same skill for the Ravens, and he's been even more productive -- 125 tackles, three sacks and two picks. He's a special player who should define the middle of Baltimore's defense for years to come.

Cornerbacks: Kyle Fuller, Chicago Bears/Bené Benwikere, Carolina Panthers

It's hard to remember how good Fuller was in the first few weeks of the 2014 season, before injuries and questionable defensive coaching tripped him up. But through the first four weeks of the season, Fuller (who went 14th overall) allowed just one touchdown to three picks, and limited opposing quarterbacks to a 56.3 rating. Since then, however, he's given up four touchdowns to no picks and an opponent passer rating of 111.5. Hopefully he can bounce back in 2015, because Fuller does have the potential to be great. Benwikere didn't allow a single touchdown in 254 snaps and 45 targets (best among rookie corners who played at least 25 percent of their team's snaps), and has played very well outside and in the slot. Not bad for a fifth-rounder from San Jose State.

Safeties: Pierre Warren, New Orleans Saints/Ha Ha Clinton-Dix, Green Bay Packers

New Orleans' defense has been a hot mess most of the season, but Warren, the only undrafted player on our list, has still distinguished himself by picking off two passes and allowing no touchdowns all season in 348 snaps. He's been burned deep from time to time, and he needs to develop as a run support player, but there's a lot to like there. Clinton-Dix was even better, allowing no touchdowns and picking off one pass in 889 snaps. The 21st overall pick, he's also proven to be a strong player in blitz packages and when asked to stop the run as a box player or force defender.