O.J. Simpson, Adrian Peterson, Jim Brown, Earl Campbell, Emmitt Smith. Accounting for different teams and different eras, which running back grades out as the greatest in NFL history? Ian Allan weighs in his vote.

Last week I put together a list of the top quarterbacks ever. It got me thinking about the other marquee position – running backs. How do we rank O.J. Simpson against Jim Brown against Barry Sanders against Adrian Peterson? I found it to be a lot harder than at quarterback – a lot less separation.

I settled on 22 finalists. Basically, I went down the list of all running backs who are in the Hall of Fame. Anybody who seemed to have some chance of being one of my top dozen backs of all time, I put him on the finalist list. Because the game and the players have changed so much, I went with modern era only – no Bronko Nagurski, no Red Grange.

Ten guys in the Hall of Fame didn’t make my list of finalists – Larry Csonka, Frank Gifford, Franco Harris, Paul Hornung, John Henry Johnson, Leroy Kelly, Floyd Little, Ollie Matson, Hugh McElhenny and John Riggins. They’re all good players (Hall of Famers) but just not good enough in my opinion to be considered one of the best of the best.

I added six other guys who either might get into the Hall, or caught my eye for some other reason – Adrian Peterson, Edgerrin James, Tiki Barber, Priest Holmes, Terrell Davis and Jamaal Charles. Bo Jackson was on the list initial, but I scratched him after brief consideration. In a handful of games, he looked really special. I think he could have been a top-5 back if he’d chosen that route in life. But he never committed to the NFL; never had a 1,000-yard season and played only parts of four seasons.

For all but four of the backs, I’ve seen them play (on television) many times. And the four older backs, I’ve seen plenty of them in highlights. Combining what I’ve seen and taking a closer look at their numbers, I offer my top 10 backs of all time:

1. JIM BROWN
He’s miles ahead of everyone else. He won eight rushing titles in his nine years. He had the awesome blend of size, speed, power and vision – you’ve seen the highlights. Had he not played in the era of 12- and 14-game seasons, he would have gone over 2,000 yards twice. He still holds the record for most games with 4 TDs. This isn’t a “fantasy” list, but he averaged 19 points per game using traditional fantasy scoring. All 21 of the other backs I looked at are under 17. Didn’t miss a game in his career. In my opinion, the only credible knock against him is that when Brown retired, Cleveland plugged in Leroy Kelly at tailback and there wasn’t much of a dropoff. Kelly ran for 1,141 yards and averaged 5.5 yards per carry in 1966, and followed that with two more 1,000-yard seasons. But Kelly was also a great running back (maybe one of the top 40 in league history). I don’t buy the premise that NFL defenses just weren’t any good during Brown’s time. We all agree O.J. Simpson was a great back, and he came into the league just four years after Brown left. Yet Simpson, didn’t make much of an impact in his first three years. But Brown was awesome from the day his career started until the day he walked away; he would have piled up the yards in any era.

2. WALTER PAYTON
He built himself into one of the true giants of the position with a remarkable offseason workout regime that was years ahead of his time. He could do it all – run, catch and pick up the blitz. Great power for a back who weighed only 202 pounds. Incredible durability; he closed his career by playing in 186 straight games – that’s a lot more impressive than Brett Favre’s quarterback streak when you factor in how much punishment he was taking. Great stiff-arm, and he liked to lower his head and initiate contact (which would get him flagged at times today).

3. BARRY SANDERS
The most electrifying runner of all time, with his stop-start ability, balance and various spin moves. He averaged 100 rushing yards per game for his career, which is No. 2 on this list behind only Jim Brown. Maybe Sanders is the best “runner” ever. But he’s not as well rounded as some of the others. He wasn’t as good running inside; I remember some games where opponents clogged up the middle and he couldn’t get much going. At times, he was a streaky hit-or-miss back. He wasn’t good in a short-yardage situations; he couldn’t soar over the line for 1-yard touchdowns like Walter Payton, LaDainian Tomlinson and Marcus Allen. I think those guys, and Emmitt Smith too, were all better on passing downs as well – as blockers and pass catchers. It would be interesting as hell to use a time machine, go back to 1989, and place Sanders on some different NFL rosters. He spent most of his career in a run-and-shoot type offense; I’d like to see what he would have done in a more traditional system.

4. LaDAINIAN TOMLINSON
A carbon copy of Payton, who was his idol. I think Payton was just a sliver better as a runner. I think Payton was a half step faster, his yards-per-carry average was a little better, and he finished his career with 3,000 more rushing yards. Tomlinson was more productive as a pass catcher – he caught 132 more passes in his career – but I think that can be attributed more to their relative offenses rather than their ability. Payton averaged over a yard more per reception. Tomlinson grades out a look better in ball security, with 56 fewer fumbles, so there’s really very little difference between these two – Tomlinson just as easily could be up in the No. 2 spot. Some of the other backs in the top 10 are better pure runners than Tomlinson, but he’s more well-rounded, and he was remarkably durable and consistent. In the first eight years of his career, he didn’t miss any games with injuries.

5. ADRIAN PETERSON
Peterson is still playing, but he’s been around for seven years, so we’ve had a chance to see what he’s all about. Awesome combination of speed and tackle-busting ability. Ran for 2,097 yards the year after undergoing reconstruction knee surgery, which hardly seems possible. Averages 5.0 yards per carry for his career, and averages 98 rushing yards per game – just behind only Jim Brown and Barry Sanders. Below-average in the passing game, compared to these backs I’m looking at. For durability, he’s well behind the four guys I’ve listed ahead of him – has missed games in four of his seven seasons.

6. O.J. SIMPSON
Maybe more talented than any of the running backs I’m listing. Had better speed, I think, than all of them. Not quickness, but speed – he’d be in the best in the 100. When he got in the open field, he was gone. Still holds the record for most career games with over 200 rushing yards. I wrote something last week about how great Pittsburgh’s defense was in the mid-70s. I remember Simpson going into Three Rivers Stadium in 1975 and running for 227 yards, getting outside for an 88-yard touchdown. Had two phenomenal seasons – 2,003 yards in 1973, then he came back two years later and had even more total yards (1,817 rushing, 426 receiving, and 23 TDs). In 1973, he averaged 143 rushing yards per game, which is 10 more than anybody else in league history. But Simpson had a much shorter career than all of other backs. He didn’t make much of an impact in his first three seasons – took him a while to get going. Then he suffered a knee injury in 1977, and he was never the same after that. When the numbers are adjusted to account for games played, Simpson, in comparison to the other 21 backs on this list, had only one other above-average season.

7. MARSHALL FAULK
Three remarkable years with the Rams, coming in at 1st, 6th and 26th out of the 232 seasons (when they are adjusted to account for guys playing different numbers of games). In comparison to the other backs here, he’s definitely below-average as a runner – definitely one of the bottom couple of the top-10 backs. But he’s the best of the pass catchers. Averaged 39 yards per game as a receiver, and was over 10 yards per catch as a receiver five times. In one three-year stretch, he averaged over 900 receiving yards. I’m downgrading Faulk some because I think some of his success must be attributed to the offensive scheme he was in. Playing in that same offensive system, Priest Holmes (who’s not even on the list) had a three-year run that was even better than Faulk’s best three years. Faulk very possibly would have been just a top-20 type back if he’d been drafted by a lot of other teams.

8. ERIC DICKERSON
Big, upright runner who hit holes decisively. Made an instant impact, running for 1,808 and 2,105 yards in his first two seasons. Combined, these 22 backs I’m looking at played a combined 232 seasons. Adjusting those to account for schedules of different sizes, Dickerson had one season in the top 10 percent, two others in the top 20 percent, and a fourth in the top 30 percent. (That’s standard fantasy scoring). Was an above-average back for each of his first six seasons (then a below-average back in his final five). He was a below-average receiver, and with 78 fumbles in 146 games, he had the worst ball security of any of the running backs I looked at.

9. EMMITT SMITH
I thought he was the hardest player in the top 10 to grade because of the talent around him. With guys like Barry Sanders, LaDainian Tomlinson, O.J. Simpson and Adrian Peterson, it’s apparent that they would have been successful on any team and in any era. Just put them behind any crappy offensive line and watch them break tackles and make people miss. With Smith, he had the benefit of running behind a great offensive line. Despite that blocking, Smith averaged only 4.2 yards per carry, which is the 4th-lowest of the players I looked at. Didn’t have a lot of speed, and my hunch is that had he been drafted by a lot of other teams, I don’t think we’d be thinking of him as a top-20 back. But production has to count for something. Smith played 15 years, and he’s the all-time leader in rushing yards and rushing touchdowns. Smith wasn’t great as a receiver; he averaged only 6.3 yards per catch during his career (the lowest of these 22 running backs). But I think he was one of the better ones in blitz pickups.

10. EARL CAMPBELL
If we’re looking for just one game or one season, than Campbell belongs in the top 5. The best wrecking-ball runner I ever saw, and with a getaway gear. He was just bigger, faster and stronger than the guys trying to tackle him – a man among boys. He piled up 1,934 yards and averaged 5.2 yards per carry in 1980. He was a one-man offense. Just line him up behind any collection of lesser blockers, and he’d grind out the yards. But running backs who dish out that kind of punishment also tend to break down themselves. Campbell was phenomenal for three years, started to dip in Year 4, and that was pretty much it. He also wasn’t a factor in the passing game, averaging under 7 receiving yards per game for his career.

OTHER BACKS

Some observations on the other running backs (in alphabetical order by first name).

Curtis Martin
When you look at the length of his career, you’d have to consider him to have a better long-term impact than Campbell. Campbell had two seasons than were better than anything Martin ever did. But of the next 12 best seasons by these two backs, all but three of them belong to Martin. He would be No. 11 on my board.

Edgerrin James
I remember seeing him break two 40-yard runs in his first preseason game and thinking he was going to be something special. Opened his career with two of the top 25 seasons of the 232 I looked at. Then become more of a Martin guy – good seasons rather than great. If not for the ACL injury in his third year, might have played his way into the top 10.

Gale Sayers
You’ve seen the electrifying runs – the Barry Sanders of the ‘60s. But not enough production, even before the knee injury that cut short his career. Only two above-average seasons when compared to these other great backs. When over 1,000 yards only twice. Would be nice to see how he would have fared with other franchises, where he might have been used more as a pass catcher.

Jamaal Charles
He might play his way into the top 10 before long. He’s averaging 5.6 yards per carry for his career, which is the best of anyone I’ve looked at. He’s averaged at least 5.0 yards per carry every year during his career. Great speed, and a good pass-catcher too.

Jim Taylor
Bruising runner powered the Packers to a bunch of championships in the ‘60s, with five straight seasons over 1,000 yards – back when it meant something. Look at the numbers and it becomes apparent that Taylor must be slotted ahead of the backs that powered the dynasties that followed Green Bay (specifically, Miami’s Larry Csonka and Pittsburgh’s Franco Harris). But not a great pass catcher, and he was helped by a great supporting cast.

Lenny Moore
Moore was the Marshall Faulk or Thurman Thomas of the late ‘50s and early ‘60s. The Colts had Johnny Unitas at quarterback, and they were doing innovative things with Moore as a pass-catching running back. He averaged over 70 receiving yards per game three times. None of the other 21 running backs I looked at (including Faulk and Thomas) ever averaged 70 receiving yards in a game. Darren Sproles is a nifty pass catcher for the Saints, who put up unreal passing numbers, but Sproles has never averaged even 45 receiving yards. Moore was huge. For his career, Moore averaged 16.6 yards per catch – lots of big plays and yards after the catch. Not used extensively enough as a runner, however, to merit consideration as one of the top 15 running backs of all time.

Marcus Allen
Three great seasons at the start of his career, but one of them was in the strike-shortened 1982 campaign (which at nine games was really more of a half-season). After that start, never ran for 900 yards in a season again. Good pass catcher, and good as a blocker, but he averaged only 4.1 yards per carry, 3rd-lowest among the running backs I looked at.

Priest Holmes
I see him as a cross between Marshall Faulk and Terrell Davis. He worked out at that same system as Faulk, which makes running backs look very good (after Holmes got hurt, recall, Larry Johnson was even better in the 2005-06 seasons). And Holmes was similar to Davis in that we’re being asked to measure a small body of work. Holmes went over 2,100 combined yards in each of his first three seasons in Kansas City, with 61 TDs. When numbers are adjusted for seasons of various sizes, those represent three of the top 7 seasons by any of these running backs (that’s total yards and touchdowns). That’s remarkable, considering the caliber of running backs we’re measuring him against. But he was a pretty ordinary back for his four years in Baltimore, so I’m guessing he would be only a good running back if we plugged him into a lot of offenses in a lot of different eras. The 1978 Oilers, I can assure you, would have no interest in trading Earl Campbell for Priest Holmes.

Terrell Davis
Two great seasons with the Broncos, and another that was very good. Outstanding in the playoffs, with eight straight games over 100 yards, helping Denver to a pair of Super Bowls. But a lot of his success can be attributed to the scheme he was playing in. Clinton Portis, Mike Anderson and Alfred Morris all ran for 1,500 yards in that offense. Injured his knee in his fifth year and was never the same.

Thurman Thomas
Good pass catcher, and eight straight seasons over 1,000 rushing yards. I brought him in to take a look. But was never in the mix to be one of the top dozen of all time.

Tiki Barber
Three straight seasons over 2,000 combined yards. Great pass catcher. Similar to Thurman Thomas. Maybe one of the top 20 running backs in NFL history, but definitely not in the top 10.

Tony Dorsett
I thought I would give him more consideration for the top 10. But he averaged only 4.3 yards per carry for his career (which is below-average for this group). No great seasons. He had only three seasons that graded out as just barely better than average, and none ranking higher than 110th. Average as a pass catcher. With 90 fumbles in 173 games, he was 2nd-worst in that area behind Eric Dickerson.

Other runners to consider if making a top-20 list: In addition to the Hall of Fame guys I mentioned earlier, I’d be looking at Ottis Anderson, Jerome Bettis, Ricky Watters, Billy Sims, Fred Taylor and Corey Dillon. I’m not guaranteeing any of those guys would be in the top 20, but they’d at least be in the discussion.