Ranking any position is really just an exercise in reviewing past performance and projecting a player's supporting cast for the future.
On any given Sunday, any one of the 45 running backs on this list could give a performance typical of the five players in Group A. In fact, almost every one of these backs has done it, with the exception of the two rookies who made the list.
As in the past, I prefer to group players in sections of five, in alphabetical order, so please don't view the last back in Group B as the 10th-best back. There will also be an arrow up (^), down (v) or flat (>) indicating where I think a player might end up at the end of the 2011 season if he stays healthy and plays 16 games.
Here are the running back groupings in alphabetical order:
GROUP A (1-5)
3. Chris Johnson, Titans (>): Johnson was fourth in rushing yards, but fell well short of his prediction to have the greatest rushing season ever. Things could get tough when Jake Locker takes the field and defenses focus on the run game.
5. Michael Turner, Falcons (>): A solid workhorse who finished third in rushing and tied for fourth in rushing touchdowns. The Falcons' passing game creates conflicts for defenses and Turner will benefit from a lot of run audibles against two-high safeties. He could have a big year.
GROUP B (6-10)
1. Jamaal Charles, Chiefs (^): Charles needs the ball even more this year. He led the NFL in explosive runs with 45 (carries of 10-plus yards), and his ratio of 10-plus yard runs to carries was off the charts at 1:5. He averaged 6.4 yards per rush last year.
2. Steven Jackson, Rams (v): A big, workhorse back who gets the tough yardage, he finished second in carries at 330. Jackson really needs the passing game to grow and another back to lighten the load, or he is going to run out of gas.
GROUP C (11-15)
2. Ahmad Bradshaw, Giants (^): Bradshaw is explosive, has more power than many think and is a threat as a receiver. He moved into the feature role last season ahead of Brandon Jacobs and had a ratio of 1:8 in 10-yard runs per attempt. He could be a free agent this year.
GROUP D (16-20)
1. LeGarrette Blount, Buccaneers (^): Hard to believe this undrafted player was released by the Titans and wound up with 1,007 yards in 13 games. He also had 32 runs of 10 yards or more (1:6 ratio per attempt). If he gets 300 carries this year instead of the 201 he had as a rookie, Blount could be a 1,500-yard back.
2. BenJarvus Green-Ellis, Patriots (>): He's in the shadow of Tom Brady, but look at his production: Tied for second in rushing touchdowns (13) and rushed for more than 1,000 yards while averaging just 14 carries per game.
3. Brandon Jacobs, Giants (>): A big, power back who had his role reduced to 147 carries. Still, he averaged 5.6 yards per rush and had nine touchdowns. Jacobs averaged a touchdown once every 16 rushes.
5. Rashard Mendenhall, Steelers (>): Fans might not forgive him for the fumble in the Super Bowl, but check his production over the whole season. Mendenhall was tied for second in rushing touchdowns (13), seventh in rushing yards (1,273) and fourth in attempts (324) for a team that went to the Super Bowl.
GROUP E (21-25)
1. Joseph Addai, Colts (v): Addai has missed 15 starts over the last four years and played just eight games last season. When he's healthy, he is still solid.
2. Jahvid Best, Lions (^): A very dangerous situational player who gets help this year from rookie Mikel Leshoure. Best will still get close to 20 touches per game and should produce like Brian Westbrook used to for the Eagles.
5. LaDainian Tomlinson, Jets (v): L.T. can still play at a high level and, if used wisely, can win games. He still pops a 10-plus-yard run once every 10 carries and is a factor in the passing game.
GROUP F (26-30)
4. Thomas Jones, Chiefs (v): Say what you want but Jones brings attitude and production to every offense he's been with.
GROUP G (31-35)
3. Ryan Mathews, Chargers (^): He played in 12 games and had 158 carries as a rookie. If he stays healthy, gets 250 carries at his 4.3-yard average and adds to his seven rushing touchdowns, then he moves up a few groups.
5. Cadillac Williams, Buccaneers (v): I would want him on my team for his work ethic and how he fought back from injuries. Williams would be perfect in St. Louis backing up Jackson.
GROUP H (36-40)
3. Ryan Grant, Packers (>): He told me he could have played in the Super Bowl, but being on injured reserve prevented that from happening. Grant is a solid zone-scheme runner who might have to move on to get the work he wants.
GROUP I (41-45)
3. Tim Hightower, Cardinals (>): Cut in the mold of Barber.