When an NFL scout evaluates a running back, the player's size, power, speed, durability and versatility all play a role in the overall assessment. Sporting News enlisted an NFL team's director of pro personnel to rank and analyze the top 20 backs based on those criteria:
1. Adrian Peterson, Vikings. He has a slight edge on Chris Johnson because he's a more physical pure power runner—and also has breakaway speed. He's working to solve issues with ball security.
2. Chris Johnson, Titans. In addition to tremendous speed, he has great body control. Although he is slightly lighter and shorter than ideal, he runs like he's bigger.
3. Steven Jackson, Rams. A big man (6-2, 231) who has amazing versatility and deceptive speed to go with sudden bursts of power.
4. Ronnie Brown, Dolphins. If it weren't for durability issues, he might be the complete NFL back. Like Jackson, he has a big body (6-0, 230) and is a good receiver. Brown has shown he can throw the ball, too.
5. Michael Turner, Falcons. He's a combination of track star and powerful zone runner.
6. DeAngelo Williams, Panthers. He runs with good power and speed thanks to strong legs. He's a home run threat on every down.
7. Frank Gore, 49ers. With his compact frame, he's in the same category as Williams. He has outstanding vision to go with speed and ability to break tackles.
8. Maurice Jones-Drew, Jaguars. Another smaller back who has powerful legs that make him tough to bring down. He excels on screens and draws.
9. Brandon Jacobs, Giants. A big, bruising back coming off a struggle in 2009. He takes a lot of hits with his upright style but delivers them, too.
10. Felix Jones, Cowboys. He fits well in Dallas' scheme and his great speed is obvious, but he can also be a good power back with deceptive strength.
11. Marshawn Lynch, Bills. Looking at him purely on the field, he is very skilled and powerful. He must show he can avoid the injury bug, however, to maintain success in Buffalo or elsewhere.
Anquan Boldin will have a huge impact with Ravens, but that's just one of the storylines in this year's camp previews. Click here for more.
12. Marion Barber, Cowboys. He always runs with a head of steam at 100 miles per hour. He knows he's big and strong and takes it out on you.
13. Cedric Benson, Bengals. He had a bad start to his career but turned the corner last year. Now, like Lynch, he just needs to get out of his own way.
14. Reggie Bush, Saints. A little change of pace here—his elusiveness stands out as both a runner and receiver. He's a great asset on screens and draws.
15. Rashard Mendenhall, Steelers. He fits the mold of a big, strong, fast back and may be ready for a breakout year with better help from his line.
16. Ray Rice, Ravens. They asked him do a lot last season, and he held up. That will be key going forward, because with his size (5-8, 205) they need to keep him from getting him too nicked up as a feature back.
17. Shonn Greene, Jets. You could have called him a dark horse to find the light in Year 2, but then you remember how great he was during the playoffs.
18. Matt Forte, Bears. He had a big rookie year before the workload caught up to him a bit in Year 2. His powerful body and versatility still stand out. Having Chester Taylor to relieve him should help.
19. Beanie Wells, Cardinals. He's a big back, but he also has the burst to rack up big yards per carry. Getting double-digit touches consistently this season will help him.
20. Jonathan Stewart, Panthers. They don't miss a beat when he replaces Williams; he would be a featured star on most teams.
Joseph Addai, Colts. It's hard to get a read on him in the Colts' offense. He may lose significant touches to Donald Brown.
Jamaal Charles, Chiefs. The little back surprised many with a big second half of the season. The Chiefs made a good move to bring in Thomas Jones, who will help keep Charles fresh and healthy.
Ryan Grant, Packers. He can be explosive, but his success may have more to do with his cutback running, which is ideal for his team's scheme.
LeSean McCoy, Eagles. He has the versatile skills to be a younger Brian Westbrook; he just needs to prove it.
Knowshon Moreno, Broncos. Moreno was nicked up a lot as a rookie, so it will take another year to determine just how good he is.
Steve Slaton, Texas. He has underrated toughness for a smaller back.
CSN: Even if Aaron Hernandez has nothing to do with his associate's murder, it's a story the "brand-conscious" Patriots want him far away from.
2013 SNF Schedule
Check out the 2013 Sunday Night Football schedule.
Latest from ProFootballTalk
Video: Football from NBC Sports
Texans' Mt. Rushmore
ProFootballTalk: Erik Kuselias, Mike Florio and the fans agree that Andre Johnson, J.J. Watt, Arian Foster and Bob McNair belong on the Texans' Mt. Rushmore, but Frank Wycheck argues that Mario Williams deserves a spot.
Check out some of the NFL cheerleaders from across the league.