The past few years have not been a great time to be a running back. The number of three-down, 1,000-yard backs has declined, and the last wave of truly great players at the position -- Adrian Peterson, Marshawn Lynch, Frank Gore, LeSean McCoy, Jamaal Charles, Arian Foster -- are mostly all retired or expected to hang up their cleats soon. But maybe there's a new wave crashing now that could even surpass what we've seen from running backs over the last 10 years.

With players like Le'Veon Bell, Ezekiel Elliott and David Johnson, we have three of the most unique players in the modern era. The same may probably be said for rookies Leonard Fournette and Christian McCaffrey, while the 2017 class potentially has a few more gems to be found in the later rounds. Most teams will still likely lean toward passing the ball, using a backfield-by-committee and doing what they can to preserve athletes in the most physically demanding position on the field, but there are at least some new superstars in the mix who could get drafted higher and paid better than what we've seen in recent years.

But it's not all good for the players or the teams.

A lot of franchises have gone so cheap at the position -- because many teams have succeeded with this method -- that they are definitely lacking talent in their running back unit. Even when you get outside of the top 10 of these rankings, it starts to become obvious how many flaws there are with the backs who are expected to be majority ball carriers. The teams that do have talent at running back, especially in an era where there also aren't many great offensive linemen, will likely enjoy a boost of success that is being overlooked right now.

Note: Some of the data used in this piece comes from Football Outsiders, including DYAR (Defense-Adjusted Yards above Replacement), DVOA (Defense-adjusted Value Over Average) and Success Rate (measuring a player's consistency based on production given the down and distance of every given play).

1. Pittsburgh Steelers: Le'Veon Bell, Fitzgerald Toussaint, James Conner*, Knile Davis, Roosevelt Nix

In the sense of a single game, there is not a better running back right now than Bell. Last season, he was worth 157 yards of offense per game and didn't even turn 25 until this past February. The only issue is Bell's ability to stay on the field -- either because of injury or suspension -- and the lack of a proven backup since the loss of DeAngelo Williams (set to test out pro wrestling). But in most games, Pittsburgh will likely have the most dangerous back in football, and that's about as much as you can ask for these days.

2. Dallas Cowboys: Ezekiel Elliott, Darren McFadden, Alfred Morris, Keith Smith

Elliott finished first in rushing yards (1,631) and scored 16 touchdowns as a rookie. In his lone playoff game, Elliott added 125 more yards on 22 carries. On the downside, he fumbled five times, plays behind an offensive line that could give Trent Richardson a 1,000-yard season and has only one year of proof that he's actually this great. It's not that I'm worried about Elliott (he is the No. 2-ranked player on the list, after all), but there are some concerns, as with all running backs. My biggest fear is the workload: He has 322 regular season carries and 377 total touches. Dallas should ramp that down and give more attention to McFadden and Morris whenever possible. Still, barring the workload taking him out of games this year, another Pro Bowl season seems like a lock for Elliott.

3. Tennessee Titans: DeMarco Murray, Derrick Henry, David Fluellen, Khalfani Muhammad*, Jalston Fowler

Just how good could the Titans' offense be this year? They have an elite offensive line and running backs, Marcus Mariota could take another step toward greatness and they've made considerable efforts to improve at receiver and tight end. Everything could still revolve around Murray and Henry, the best running back duo in the game today. The Titans' offensive numbers could be even more inflated because they frequently play against AFC South defenses.

4. Arizona Cardinals: David Johnson, Andre Ellington, Kerwynn Williams, T.J. Logan*

If there was a better, more complete back than Bell last season, it was probably not Elliott; it was Johnson. He had a league-high 2,118 yards from scrimmage and 20 touchdowns and became the first player in history to put up at least 100 total yards in each of his team's first 15 games. He was held back from doing it for a 16th time because of a knee injury. That injury was not serious, and he should be in MVP talks if the Cards can get back to the playoffs.

5. Buffalo Bills: LeSean McCoy, Jonathan Williams, Mike Tolbert, Patrick DiMarco

Buffalo lost Mike Gillislee (surprisingly fourth in DYAR, first in success rate), but 2016's top rushing offense -- first in rushing yards, touchdowns and yards per carry -- shouldn't skip a beat as long as McCoy is around.

6. Atlanta Falcons: Devonta Freeman, Tevin Coleman, Brian Hill*, Derrick Coleman, Terron Ward

It may seem low for a team that had two running backs who combined for 1,599 yards and 19 touchdowns on the ground, plus another 883 receiving yards with five more touchdowns, but I don't think Freeman and Coleman are major standouts on their own. Ultimately, Freeman is "pretty good" and Coleman is a small step behind him. Together it's a good combo, but separately how would they do on their own?

7. Jacksonville Jaguars: Leonard Fournette*, T.J. Yeldon, Chris Ivory, Corey Grant, Marquez Williams*

Is this too high of a ranking for a team leading the charge with a rookie? I don't believe so, given that Fournette is a better prospect than Elliott was a year ago. The Jags have a much worse offensive line than Dallas, so he may not shine as brightly on the stat sheet as a rookie. Ivory and Yeldon finished last and third-to-last in DYAR, but as backups, either could be a decent option.

8. Cincinnati Bengals: Jeremy Hill, Giovani Bernard, Joe Mixon*, Cedric Peerman, Brandon Wilson*

Perhaps no team has put more effort into drafting a stable of running backs in recent years than the Bengals. Whether or not that is a smart strategy, given how easy it's been for teams to find good backs on the cheap, remains to be seen. Mixon is the third back that Cincy has drafted in the second round since 2013, and the spotlight will remain on the Bengals after that pick, given his high-profile assault of a woman in 2014.

9. Chicago Bears: Jordan Howard, Jeremy Langford, Benny Cunningham, Tarik Cohen*, Ka'Deem Carey, Paul Lasike

Howard had 1,313 rushing yards, 5.2 YPC and 298 receiving yards, and he finished fifth in DYAR on a 3-13 team. The Bears did a lot of things wrong last year, but picking up Howard with the 150th overall selection wasn't one of them. Chicago also has surprisingly good run blocking, so expect more quality production from Howard in 2017, even if the Bears will struggle to approach a .500 record once again.

10. Miami Dolphins: Jay Ajayi, Kenyan Drake, Damien Williams, Storm Johnson

Ajayi had three 200-yard games last season, making him a fantasy star for a week or two, but then he also had a considerable number of concerning games, including a 16-carry, 33-yard performance in Miami's wild card loss to Pittsburgh. Drake has interesting potential but didn't get much run as a rookie -- a trend that continued from his time at Alabama -- so it's hard to say what his future holds.

11. New Orleans Saints: Adrian Peterson, Mark Ingram, Alvin Kamara*, Travaris Cadet, Daniel Lasco, John Kuhn

The Saints' running back group look decent not because of Peterson, but because with Ingram and Kamara -- who was one of the most intriguing prospects coming out of this year's combine -- they have three guys who could start. Even Cadet and Kuhn have proven useful.

12. New England Patriots: Mike Gillislee, James White, Dion Lewis, Rex Burkhead, James Develin, Brandon Bolden

This could be considered high for New England, given its lack of a star No. 1 back and the loss of LeGarrette Blount, but that's just how good Bill Belichick has been at stocking the roster without spending a lot of money or draft picks at this position. With a larger sample size, maybe Gillislee isn't as successful on a per-play basis, but that won't be an issue with the Patriots, where the workload will continue to be spread around. Burkhead would have finished second in DVOA if he had qualified with a few more attempts in Cincinnati. Lewis and White were effective in small samples, as well, while Develin also signed a two-year deal. Yeah, the Patriots are really annoying, but if this seems high right now, consider that they might only look better as the year goes on.

13. Los Angeles Chargers: Melvin Gordon, Branden Oliver, Kenneth Farrow, Derek Watt, Andre Williams, Kenjon Barner

Gordon was considered by some to be a breakout player last season because he nearly had 1,000 yards and scored 10 times, but advanced stats tell a different tale. Gordon ranked 31st in DYAR, 30th in DVOA and 26th in success rate, while averaging just 3.9 yards per carry. He exhibited the big-game potential he showed as a 15th overall pick with a 196-yard performance against the Titans (with 65 more yards through the air), but he disappeared too many times.

14. Los Angeles Rams: Todd Gurley, Lance Dunbar, Malcolm Brown, Aaron Green, Sam Rogers*

Gurley was the lone bright spot on the Rams offense in 2015, and then he became the unit's biggest disappointment a year later; that's saying something given the number of disappointments on the Rams. His yards per carry dropped from 4.8 to 3.2 and he finished 37th in DYAR, behind such players as Thomas Rawls, Matt Asiata and Jerick McKinnon. He has the potential to be great, but there's also a chance that the Rams will end the season with the worst RB unit in the NFL because there isn't any depth.

15. Seattle Seahawks: Eddie Lacy, Thomas Rawls, C.J. Prosise, Alex Collins, Chris Carson*, Mike Davis

In their best-case scenario, the Seahawks have Pete Carroll's dream: The best rushing offense in the NFL again. Lacy was a great, relatively low-cost option if he stays fit and healthy, but that's understandably a concern given his history. Rawls led the NFL in DYAR and YPC in 2015, but injuries took away his chance at a notable sophomore campaign. Prosise was phenomenal in short stretches, but he also couldn't stay on the field, averaging 5.7 YPC but on only 30 carries.

16. San Francisco 49ers: Carlos Hyde, Tim Hightower, Joe Williams*, Kyle Juszczyk, Kapri Bibbs

Over one 10-game stretch last season (all losses), Hyde averaged 83 yards/game and 4.96 YPC and scored six times. That's an impressive accomplishment for the second-worst team in the league. Still, his career has been marred by injuries, inconsistency and playing for Jed York. The addition of Juszczyk, the NFL's top fullback, also shouldn't be ignored. The 49ers will be abysmal once again, but this unit could be average or better.

17. Carolina Panthers: Jonathan Stewart, Christian McCaffrey*^, Curtis Samuel*^, Cameron Artis-Payne, Fozzy Whittaker, Alex Armah*

I make this list with the note that McCaffrey is more like a running back who plays slot, and Samuel is more like a receiver who could play some running back. Stewart struggled last season, as most Panthers offensive players did, but he's proven to be reliable and could be effective again.

18. Green Bay Packers: Ty Montgomery, Jamaal Williams*, Aaron Jones*, Devante Mays*, Aaron Ripkowski

Montgomery is a unique back, given his transition from receiver/returner to a player who had 77 carries and 5.9 YPC last season, and that could work for or against Green Bay long-term. The Packers also drafted three running backs to insure themselves if Montgomery ends up moving back to receiver, which gives them intriguing depth but not any proven options.

19. Philadelphia Eagles: LeGarrette Blount, Ryan Mathews, Darren Sproles, Wendell Smallwood, Donnel Pumphrey*

Blount led the NFL in rushing touchdowns, but he did so on the NFL's best team, with the NFL's best quarterback, and he's turning 31 this year. Overall, the Eagles have a stable of one-dimensional backs that they hope come together and work as a unit to provide the same value as one excellent back -- almost like a football's Voltron.

20. Oakland Raiders: Marshawn Lynch, Jalen Richard, DeAndre Washington, Taiwan Jones, Elijah Hood*, Jamize Olawale

It's hard to judge Lynch as much of anything right now after taking 2016 off and struggling in his final stint with the Seahawks in 2015. That being said, he should get Hall of Fame consideration, Oakland has exceptional blocking and he seems extremely motivated. Richard and Washington look like solid backups.

21. Minnesota Vikings: Dalvin Cook*, Latavius Murray, Jerick McKinnon, C.J. Ham

The Vikings were the worst rushing team in the NFL, so before we get ahead of ourselves after they added Cook (41st overall pick) and Murray (a lot of touchdowns, not much consistent success), let's see if the team remembers how to run it at all.

22. Washington Redskins: Rob Kelley, Chris Thompson, Samaje Perine*, Matt Jones

You may not think of Washington as a rushing team, but it finished ninth in YPC with improvements across the board from Kelley, Jones and Thompson. Perine's 427-yard game against Kansas in 2014 remains an FBS record. This is a quality group that may or may not have an exceptional starter in the mix.

23. Kansas City Chiefs: Spencer Ware, C.J. Spiller, Charcandrick West, Anthony Sherman, Kareem Hunt*

Ware has had a nice resurgence with Kansas City after flaming out in Seattle, but is he a good long-term option as a starter? Spiller has basically proven that he's also likely just a complementary back, and he's struggled to stay on any team for very long in the last couple of years. The future may be Hunt, a third-rounder, but that's far from a sure thing.

24. Cleveland Browns: Isaiah Crowell, Duke Johnson, Dan Vitale, George Atkinson, Matt Dayes*

Crowell has some new fans out there after he posted four 100-yard games in 2016, including a run of 87 yards, the longest in the NFL last season. But he averaged 3.5 YPC or less in nine of his starts. He ranked 40th in success rate.

25. New York Jets: Matt Forte, Bilal Powell, Elijah McGuire*, Brandon Wilds

Forte is probably done as a lead back (3.9 YPC over his last 43 games), but the Jets will likely share the responsibility between him, Powell (who had an underrated finish of eighth in DYAR and third in DVOA) and McGuire. This committee may be the one thing to watch on offense next season. In fact, if they do too well, the Jets might have to release Forte to help ensure their "tanking" plan.

26. Denver Broncos: C.J. Anderson, Jamaal Charles, Devontae Booker, De'Angelo Henderson*, Andy Janovich

The Broncos' struggles last season were potentially rooted not in their quarterback, but in their imploding run game that finished 28th in YPC. Anderson and Booker were rarely productive, and Charles can't even be considered a lock to make the final roster. This group has intriguing potential, but the situation is also quite volatile.

27. Houston Texans: Lamar Miller, Alfred Blue, D'Onta Foreman*, Tyler Ervin, Jay Prosch

In a world where Brock Osweiler's contract was clearly the worst of 2016, we seem to overlook another Rick Smith mistake from last year's free agency: Lamar Miller's $26 million deal. First of all, in today's NFL, no one should pay running backs like that unless they're really special. Second of all, Miller wasn't exceptional with the Dolphins, which is why they let him leave. His first season in Houston resulted in 1,073 yards but only five touchdowns, 4.0 YPC, two fumbles, two missed games and a 35th finish in DYAR. Foreman was a fairly polarizing prospect because his 2,000-yard season with Texas came almost exclusively against terrible defenses, but perhaps he'll prove his doubters wrong over time.

28. Baltimore Ravens: Terrance West, Danny Woodhead, Javorius Allen, Lorenzo Taliaferro, Kenneth Dixon (suspended four games)

West squandered a few good starts last year by averaging just 3.5 YPC over the final 11 games, while Woodhead's ability to recover from a torn ACL at age 32 remains to be seen. They lost Juszczyk and will likely finish near the bottom in most rushing categories.

29. Indianapolis Colts: Frank Gore, Robert Turbin, Troymaine Pope, Marlon Mack*

Gore deserves credit for having a phenomenal career that included another 1,000-yard campaign at age 33 last season. That being said, only two players have ever topped 1,000 yards after age 33: John Riggins, who did it twice and even led the NFL in rushing touchdowns in both of those seasons, and John Henry Johnson in 1964. The only running back in this century to even rush for more than 500 yards after age 33 is Emmitt Smith. (Rich Gannon rushed for 529 yards at age 35 in 2000.) Gore's odds of a high level of success are low and his backups aren't likely to become starters.

30. Tampa Bay Buccaneers: Doug Martin (suspended three games), Jacquizz Rodgers, Charles Sims, Jeremy McNichols*, Peyton Barber, Alan Cross

Even if Martin weren't suspended for three games, this group would look pretty awful. Martin is wildly inconsistent, averaging 2.9 YPC in 2016. There isn't anyone in this group who you can confidently say will still be on the Bucs by the start of the 2018 season.

31. New York Giants: Paul Perkins, Wayne Gallman*, Shaun Draughn, Shane Vereen, Orleans Darkwa

Perkins is worth watching, as he put up 102 yards in the season finale, but he's yet to prove anything and the Giants have shown little interest in trying to improve their 29th-ranked running game, which also finished last in rushing touchdowns. Gallman and Perkins seem like low-ceiling players who are still young, while Draughn and Vereen are also low-ceiling players, but old.

32. Detroit Lions: Ameer Abdullah, Theo Riddick, Zach Zenner, Matt Asiata, Dwayne Washington

The Lions weren't successful at running the ball, but they didn't make any significant changes because they're still going to focus on Matthew Stafford as the one who brings the Lions down the field. Riddick led the team with just 357 rushing yards, but Abdullah is expected to be the one to bring this unit out of the gutter. Abdullah's career high for yards in a game is 77.