The other day, Cal from Los Angeles had an interesting question for the mailbag.
He looked at the incredible class of free-agent running backs scheduled for 2012. The contracts of Adrian Peterson, Ray Rice, Matt Forte, Peyton Hillis, Ryan Grant, Reggie Bush and Frank Gore all expire after the 2011 season. Athletes often play their best in contract years.
So Cal wondered if that type of incentive could turn this into the "Year of the Running Back."
Figuring out the dynamics of runners is one of the most puzzling parts of this strange, labor-infected season. The NFL remains a quarterback-driven league, and that isn't expected to change because of the lockout. But logic says runners should have increased value for a couple of non-labor reasons.
More teams than normal could be breaking in young quarterbacks such as Andy Dalton, Christian Ponder, Jake Locker, Cam Newton and Tim Tebow, and if that is the case, you would expect those offenses to run the ball more to take pressure off their young quarterbacks.
Then there's the contract year theory, which bears further study. The more you look at it, the pressure of playing for big money may not necessarily turn this into a big year for backs. The simple reason is the position. Running backs have one of the most humbling jobs in sports.
Unlike virtually any other position in football, backs aren't drafted for the long haul. Hall of Famer Eric Dickerson has long said the top lifespan for a back is six years and 1,600 carries. Like automobiles, backs depreciate in value more than any other player in a sport.
Once a back gets to the age of 28 or 29, teams are usually looking to replace him. Backs drafted in the first round get five-year contracts, but there have been only a handful of first-round backs taken since 2000 who received a second long-term contract with the teams that drafted them.
To start, all you have to do is look at this year's class of free-agent runners. Joseph Addai of the Colts was in the last year of his contract last season. He gained only 495 yards. Ronnie Brown of the Dolphins was playing for a contract last year. Now, he's a free agent coming off a 734-yard season and recently said he wonders if the Dolphins will re-sign him. Cadillac Williams of the Buccaneers was in a contract year last season and gained only 437 yards.
As you look through the 2000s, there aren't many examples of backs who hit their best seasons during a contract year. Shaun Alexander of the Seahawks is a glaring exception. He gained 1,696 yards in the final year of his rookie contract and then followed it up with an 1,880-yard season playing under the franchise tag.
Often, though, by the fourth year of a top back's career, contract problems usually boil over to a point of a holdout. It happened with Larry Johnson of the Kansas City Chiefs. Johnson held out of camp in 2007 and never was the same back once he got his money. Jamal Lewis of the Ravens had a 2,066-yard season in his fourth year, but contract issues over the next couple of seasons ultimately led to his departure to Cleveland.
Chris Johnson of the Titans isn't a free agent in 2012 because he's only three years into his career, but you can almost assume he's going to hold out. The Titans slightly upgraded his contract last season with thoughts of doing a big deal in 2011. But the lockout has prevented any contract talks between Johnson and the team, and it will be hard to throw together such a big deal before the start of this camp. There just isn't enough time.
As for Peterson, you figure he should have a monster year in 2011. He's one of the best backs of this era. The NFL Network polled players around the league for its top 100 players and Peterson finished third. The great ones usually conquer challenges. Last year, Peterson was challenged to fix a fumbling problem. He ended up with only one fumble and vows not to have any this season.
He won't fumble the chance to play for a big deal in a contract year.
Rice is such a dedicated worker that he should put up great numbers in the final year of his contract. As for the rest, it's hard to tell. Some backs are now a little older, which makes it tough. Others are playing in offenses undergoing some type of transition.
And all backs are operating without the benefit of having real offseason workouts, which help with timing and building chemistry with offensive lines.
Face it: Backs have their backs against the wall every season, and this one is no different.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.