Eric Mack
Friday July 8th, 2011

It is well known the career-span of an NFL running back is five to six years. A fantasy team's life-span can be less than five to six games if you don't draft the position wisely.

Tracking player movement, depth charts and injury news are imperative in training camp as it relates to running backs. Doing so could have netted you the find that was Arian Foster a year ago. You could have also helped avoid the bust that was the Jets' Shonn Greene, because LaDainian Tomlinson looked so capable in the preseason.

Quarterbacks might score the most points and the wide receivers might be the showy divas, but fantasy football still revolves around the backs. Even the age of running back committees has enhanced this fact. It has made the position deeper and forces fantasy owners to draft more and more backs ... just in case one becomes the workhorse.

We have already taken an early look at the QBs, here are how the RBs breakdown in to tiers (as in, if your early round RB breaks down, you will be in tears):

1. Adrian Peterson MIN 2. Chris Johnson TEN 3. Arian Foster HOU

These are the true No. 1 overall candidates. And, like the top five QBs, you could order them in any way. We place Foster third coming off his breakthrough season, because he came out of nowhere and will have to deal with a prospect (see the middle of Tier VII below) stealing carries.

Peterson and Johnson would be more certain No. 1s if they had better QB situations around them. Maybe Donovan McNabb could join one of them? If either gets a solid veteran to slot ahead of the early round QB their teams picked, move him up to No. 1 overall.

4. Jamaal Charles KC 5. LeSean McCoy PHI 6. Ray Rice BAL 7. Rashard Mendenhall PIT 8. Darren McFadden OAK

This is still an intriguing group of rushers. In fact, all of the top eight picks in fantasy this year should be RBs.

McCoy and Charles are in potentially dynamic offenses, which is why they lead the group, but all five of these still could challenge to be the highest-scoring back in fantasy this year. Rice would be a dynamo already in the linchpin tier if he didn't have a TD vulture gobbling up his goal-line carries. If he doesn't, move him up to the top at No. 4 overall.

9. Maurice Jones-Drew JAC 10. Frank Gore SF 11. Steven Jackson STL 12. Michael Turner ATL 13. Matt Forte CHI 14. Peyton Hillis CLE

This is the group of rushers most likely to suffer an injury-related breakdown. It makes them risky picks in Round 1. You might be better off selecting a QB or a WR at the back end of the first round and then taking what's left of this group. All of them have their warning signs.

MJD is the one who just dropped into this tier. He has said publicly his knee is not 100 percent and the Jags want to give his backup more carries to lessen the workload. A healthy MJD belongs in the top tier. It doesn't appear we are going to get a healthy MJD to start the season with, though.

15. Ahmad Bradshaw NYG 16. BenJarvus Green-Ellis NE 17. DeAngelo Williams CAR 18. Shonn Green NYJ 19. Ryan Mathews SD 20. Jonathan Stewart CAR 21. Knowshon Moreno DEN 22. Ryan Grant GB 23. LeGarrette Blount TB 24. Cedric Benson CIN 25. Felix Jones DAL 26. Jahvid Best DET

A 12-team, two-RB, no-flex format makes all but two of these players starters in a standard league. Offseason movement or preseason injuries will likely reduce this tier to just 24.

Everyone in this group still has 1,000-yard, 10-TD potential but they either have yet to prove it or will have to deal with a time-share. Unless you are really going to load up on backs in the middle rounds on draft day, you should try to have at least two from the top four tiers on your team through Round 4.

27. Daniel Thomas MIA 28. Mark Ingram NO 29. Marshawn Lynch SEA 30. Joseph Addai IND 31. Fred Jackson BUF

This group should represent the amount of backs who are standard starters in leagues with a flex option. There is 1,000-yard, 10-TD potential here, but time-shares make it far less likely than those in the fourth-tier.

Thomas and Ingram, likely back-to-back, should be the first rookies off the board. Thomas gets the edge right now because he is projected to start. If the Dolphins add a starter like DeAngelo Williams in the coming weeks, move Williams up and slide Thomas out of this group altogether. Ingram will have to deal with the time-share the Saints like all of their players in; otherwise, he could have been a candidate for the top 15 overall.

Lynch and Addai are nice sleepers that can move up a tier, too. The former resurrected his career after the trade to Seattle, while the latter is a third-tier back (a fantasy starter) if he proves healthy and worthy of full-time duty in training camp.

32. Brandon Jacobs NYG 33. LaDainian Tomlinson NYJ 34. Ronnie Brown MIA 35. Pierre Thomas NO 36. Reggie Bush NO 37. Ryan Williams ARI 38. C.J. Spiller BUF 39. Ryan Torain WAS

There are varying degrees of potential here, depending on how much time these players actually earn in the preseason. With full-time roles, they can be viable fantasy starters. At this point, you have to assume they are going to be backups for their teams and fantasy owners initially.

The top five of this group has injury question marks to boot. The bottom three has talent, but they are less likely to be trusted to carry the load initially. If one of that latter trio does, though, look out for a potential breakthrough.

40. Thomas Jones KC 41. Roy Helu WAS 42. Michael Bush OAK 43. Beanie Wells ARI 44. Montario Hardesty CLE 45. Mikel Leshoure DET 46. Rashad Jennings J 47. Demarco Murray DAL 48. Mike Tolbert SD 49. Donald Brown IND 50. Justin Forsett SEA 51. Tim Hightower ARI 52. Cadillac Williams TB 53. Danny Woodhead NE 54. Willis McGahee BAL 55. Ben Tate HOU 56. Delone Carter IND 57. Tashard Choice DAL 58. Marion Barber DAL 59. Brandon Jackson GB 60. Ricky Williams MIA 61. Toby Gerhart MIN 62. Joe McKnight NYJ 63. Javon Ringer TEN 64. Clinton Portis WAS 65. Keiland Williams WAS 66. Darren Sproles SD

Here is the largest group of backs and those most likely to shuffle both in and out of its own tier. You are likely to find value in most of these guys in the latter rounds for when they come into starts, or a significant number of carries.

A lot these players will get picked solely because their fantasy owners drafted the starters ahead of them in the earlier rounds. The young unknowns in Helu, Hardesty, Leshoure, Murray, Tate, Carter and Keiland Williams have the highest ceilings of the bunch.

67 Mike Goodson CAR 68 Chris Ivory NO 69 Shane Vereen NE 70 Kendall Hunter SF 71 Anthony Dixon SF 72 Jacquizz Rodgers ATL 73 Brian Westbrook SF 74 Jason Snelling ATL 75 Dion Lewis PHI 76 Tiki Barber FA 77 Jalen Parmele BAL 78 Isaac Redman PIT 79 Jordan Todman SD 80 Taiwan Jones OAK

Those above are more likely to be on and off the waiver wire than get drafted at all in standard leagues. We have to mention them in the event they get carries, though.

The rookies of the group -- Vereen, Hunter, Rodgers, Lewis, Todman and Jones -- are the ones most likely to wind up as fliers on draft day.

As you can see, there are still a lot of chips to fall in the coming month to firm up these rankings. But the best policy with drafting running backs remains the same: pick them early and often.

Eric Mack writes fantasy for You can mock him, rip him and (doubtful) praise him before asking him for fantasy advice on Twitter @EricMackFantasy. Hit him up. He honestly has nothing better to do with his free time.

ON SALE SOON: Sports Illustrated's Fantasy Football 2011 issue tells you where all the free agents landed and what their fantasy impact will be, along with the critical draft strategy and stats analysis you need to win your league. Available in mid-August.

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