Picking the NFL's top running backs? A relatively easy proposition. Start with Adrian Peterson, add in clear-cut stars like Ray Rice, Doug Martin, Arian Foster and it doesn't take long to split the best from the rest.
Figuring out where each team's overall backfield ranks is a little trickier proposition.
How do you weigh a team with an upper-echelon lead back and a depleted depth chart behind him? Or how about the teams with two or three solid backs but no real unstoppable talents? Oh, and what to do with the fullbacks?
The rankings here try to take into account everything the 32 NFL backfields have to offer, in order to determine the top combos. Have at it:
1. Baltimore Ravens (Ray Rice, Bernard Pierce; FB Vonta Leach)
2. Houston Texans (Arian Foster, Ben Tate; FB Greg Jones)
3. Minnesota Vikings (Adrian Peterson, Toby Gerhart; FB Jerome Felton)
4. Seattle Seahawks (Marshawn Lynch, Christine Michael, Robert Turbin; FB Michael Robinson)
5. San Francisco 49ers (Frank Gore, Kendall Hunter, LaMichael James; FB Bruce Miller)
6. Tampa Bay Buccaneers (Doug Martin, Brian Leonard; FB Erik Lorig)
Pretty simple formula to land up here: combine a bona fide No. 1 back with a solid No. 2 and a steady fullback. Peterson is the best running back and arguably the best player in football, but the Vikings sit third here. Why? Because the drop-off from Peterson to Gerhart is far more substantial than the one from Ray to Pierce or Foster to Tate.
Both Pierce and Tate could start for at least a quarter of the teams in the league -- and each may get his shot with his current team down the line. It's debatable whether you could say the same for the other backups in Tier 1, though Michael and James have a ton of as-yet-untapped upside.
A fullback is not a necessity for a team to have success on the ground, and there are plenty of teams thriving without really utilizing that position. When we're talking about the top overall backfields in the league, though, it's impossible to ignore proven players such as Leach, Jones or even the underrated Robinson.
7. New England Patriots (Stevan Ridley, Shane Vereen, LeGarrette Blount)
8. Atlanta Falcons (Steven Jackson, Jacquizz Rodgers)
9. Philadelphia Eagles (LeSean McCoy, Bryce Brown)
10. Buffalo Bills (C.J. Spiller, Fred Jackson)
11. Chicago Bears (Matt Forte, Michael Bush)
And speaking of teams that can grind the opposition down without a fullback ... Atlanta, Buffalo and Chicago each got around 200 snaps out of a combination of players at fullback last season, but these backs do a lot of their work without the benefit of a lead blocker. Guys like McCoy and Spiller may have claims to higher spots in terms of straight RB1 rankings, as each is a terrific dual threat when healthy. However, each has a question behind him -- McCoy with the young, unproven Brown; Spiller with the rapidly aging Jackson -- and is moving into a new offense this season. Those changes could play to the benefits of McCoy and Spiller, but the jury is out until the regular season.
Both the Jackson/Rodgers and Forte/Bush combos pretty much are what they are at this point: consistent and usable out of different sets, but probably past their peak at both the starting and backup spots.
The Patriots' group may have the most room to improve. Ridley rolled to more than 1,200 yards last season, despite minimal help from Vereen and Danny Woodhead. The former appears primed to up his production as a do-everything weapon for New England this year.
12. New Orleans Saints (Pierre Thomas, Mark Ingram, Darren Sproles)
13. Tennessee Titans (Chris Johnson, Shonn Greene; FB Craig Stevens)
14. Kansas City Chiefs (Jamaal Charles, Knile Davis)
15. New York Giants (David Wilson, Andre Brown; FB Henry Hynoski)
16. Detroit Lions (Reggie Bush, Joique Bell, Mikel Leshoure)
17. Cincinnati Bengals (BenJarvus Green-Ellis, Giovani Bernard)
18. Cleveland Browns (Trent Richardson, Brandon Jackson)
19. Washington Redskins (Alfred Morris, Roy Helu; FB Darrel Young)
20. Jacksonville Jaguars (Maurice Jones-Drew, Justin Forsett, Denard Robinson)
A moment of honesty: I could have crafted a case for pretty much every group here to be bumped up, in most cases into the next tier. In each case, a nagging concern held them back.
For the Saints, Giants and Browns, it was wanting to see more consistency on the ground. Richardson obviously had an impressive rookie season, but can he stay in the lineup and get up over 1,000 yards? Are Ingram and Wilson on the verge of taking the next step or will they struggle to be lead dogs?
The Titans' and Lions' backfields could outperform these spots, if their No. 1 guys revive their former glories. The backup situations for each are better than people may realize. Cincinnati has a nice 1-2 punch, too, even if Green-Ellis is more a known commodity now than a dynamic back. Washington, Jacksonville and Cleveland do not have the luxury of such a safety net. There would big trouble afoot if the starter drops off any of those depth charts.
And then there's Kansas City. How does it settle at 14 when Philadelphia, with a similar situation (standout No. 1 back, risky No. 2), is up at 9? Blame it on the degree of uncertainty surrounding Charles' backup, Davis. At least in Brown, the Eagles have a player who's been through an NFL season.
21. Indianapolis Colts (Ahmad Bradshaw, Vick Ballard; FB Stanley Havili)
22. Dallas Cowboys (DeMarco Murray, Lance Dunbar)
23. Oakland Raiders (Darren McFadden, Rashad Jennings; FB Marcel Reece)
24. San Diego Chargers (Ryan Mathews, Danny Woodhead; FB LeRon McClain)
25. Denver Broncos (Montee Ball, Ronnie Hillman, Knowshon Moreno)
26. Carolina Panthers (Jonathan Stewart, DeAngelo Williams; FB Mike Tolbert)
27. Green Bay Packers (Eddie Lacy, James Starks, Jonathan Franklin; FB John Kuhn)
A real mish-mash of groups here, from those banking on a youngster (Denver and Green Bay) to those hoping their injury-prone group can survive (Indianapolis, San Diego, Carolina) to a couple teams needing bounce-back years from their talented starters (Dallas and Oakland).
For the latter two units, this is a matter of perception vs. reality. Murray and McFadden may be two of the more talented backs in the NFL, but for various reasons have not shown that consistently. Same goes for the Stewart/Williams duo in Carolina, which has had one or the other injured -- currently it's Stewart who will start the season on the PUP and miss at least six weeks -- on what feels like a weekly basis.
Don't sleep on Indianapolis. Bradshaw is another brittle body, but he has a pair of 1,000-yard rushing seasons and will be a terrific help to Andrew Luck as a pass-protector.
28. Miami Dolphins (Lamar Miller, Daniel Thomas; FB Evan Rodriguez)
29. Pittsburgh Steelers (Le'Veon Bell, Isaac Redman, Jonathan Dwyer; FB Will Johnson)
30. St. Louis Rams (Daryl Richardson, Isaiah Pead, Zac Stacy)
31. Arizona Cardinals (Rashard Mendenhall, Ryan Williams, Stepfan Taylor)
32. New York Jets (Chris Ivory, Bilal Powell; FB Tommy Bohanon)
There is a lot of "Prove Me Wrong" potential down here. Plenty of people are high on Miller, though Thomas is far from special as a secondary option there. The Steelers likely will be better than the sum of their parts, especially if Bell comes back from injury and takes charge as the No. 1; without him, they're left with the very average duo of Redman and Dwyer.
The sky may be the limit for the Rams' trio of backs. The problem is that Richardson is the only one we have seen, and he's had less than 100 career carries. Until he, Pead or Stacy really takes charge as a full-time guy, St. Louis may have to grind out yards on the ground.
Mendenhall at least provides Arizona with a potentially legit No. 1 back -- he rushed for an average of 1,103 yards from 2009-11, before an injury-plagued 2012. The Cardinals also hope rookies Stepfan Taylor and Andre Ellington develop, but neither leaps off the page.
And the Jets ... the poor Jets. Ivory, 25, still has a chance to be real good in this league. But he showed next to nothing in the preseason, pushing Powell back into the mix. If one or the other steps up, the opportunity is there. GALLERY: Check out which running backs are on the All-Overrated team