Free agency in the NFL is perhaps the most unique period of player movement in all of professional sports. Teams that attempt to build a championship-caliber squad via free agency tend to fall flat on their faces, while organizations who rely on acquiring the key pieces in the draft flourish.
The team-centered nature of football places a tremendous amount of emphasis on scheme and game planning. It's impossible to look at a stat sheet and accurately prognosticate a player's production after shifting squads.
There are obviously exceptions to this rule. Nobody ever thought Peyton Manning's move from Indianapolis to Denver would affect his production. However, for every Peyton Manning, there is an Albert Haynesworth, Nnamdi Asomugha, Laurent Robinson or John Carlson.
Free agency can be beneficial for a team looking to fill holes on its roster, but it's rare that a big-name signing ever lives up to his contract. The elite general managers across the league have the ability to attract quality players that come with reduced price tags.
Let's take a look at four players in the upcoming free-agent class that could have some surprise value in 2013.
Chicago Bears backup quarterback Jason Campbell.
Jason Campbell is one of the few veteran free-agent quarterbacks out there that has proved himself as a starter in this league. He's not a franchise quarterback that one can build a team around. However, given a solid defense and a strong running game, Campbell can be a cheap, capable, veteran quarterback for a lot of teams.
In a season in which a bevy of either unproven or washed-up NFL quarterbacks are going to hit the free-agent market, Campbell will play for $1-2 million on a one-year contract. In his last 19 games as a starter in Oakland, he had a quarterback rating just over 84. He threw for nearly 4,000 yards and had 19 touchdowns to 12 interceptions.
He's not a game changer, but for the money Campbell is much safer than Michael Vick, Matt Flynn, Alex Smith or even Mark Sanchez. Neither of the aforementioned players have proved an ability to play productively in the NFL this season, while Campbell has sat on the bench after coming off two productive seasons.
In a draft class without a franchise quarterback, Campbell could be a great fit for a team looking for a one-year, stop-gap player who can play for cheap and without embarrassing the franchise. At the very least, Campbell would be one of the most talented backups in the league and provides insurance to a team with injury-prone quarterbacks.
New York Jets tight end Dustin Keller.
Dustin Keller's production has been massively curtailed by Mark Sanchez's ineptitude and the New York Jets' lack of talent at wide receiver. Keller is just about the only pass catcher on the roster capable of making plays in the middle of the field.
His value will be lessened this offseason because of an injury-plagued 2012 campaign. After not missing a game for his first four seasons, Keller only took the field eight times this year. He finished with 28 catches for just 317 yards, both career lows.
However, Keller is just a year removed from leading the Jets in receiving while catching 65 balls in 2011. He's improved as a run-blocker and is an excellent athlete. Given the right offense, Keller could develop into a legitimate downfield passing threat.
For a guy who's most likely going to sign for a reasonable price, it's worth risking that he can return to form in 2013.
Jacksonvill Jaguars linebacker Daryl Smith.
Darly Smith only played two games in 2012 due to a groin injury. He's turning 31 next season and can't be expected to be the player he was during his prime in Jacksonville.
However, his stock is at an all-time low, and he could prove to be a diamond in the rough for a team looking for linebacker help.
Smith has been a mainstay in Jacksonville over the last nine seasons. He has good size at 6'2" and 248 pounds, great speed and tackles well in the open field. Smith is also versatile in that he is more than capable of dropping into zone coverage or running with a tight end down the field.
He has to prove he can still play after missing nearly all of 2012, but he could provide All-Pro production at a bargain price.
Any team that is looking for linebacker help should watch film of Daryl Smith. He flies around the football field and makes plays like only an elite NFL linebacker can. He could be a candidate to win the Comeback Player of the Year award next season.
Domenik Hixon stayed healthy for the first time in two seasons in 2012, and he developed into a vital aspect of the New York Giants offense. Hixon can return punts, play in the slot, on the outside or he can run block.
Even after tearing two ACLs in as many seasons, Hixon proved this season that he still has the breakaway speed to be productive in the NFL.
With Hakeem Nicks, Victor Cruz and Rueben Randle lining the Giants' depth chart for next season, Big Blue will likely let Hixon walk if he wants a significant contract. However, he's a deep threat with impressive catching ability that will play for No. 3 receiver money.
There are better wideouts on the market than Hixon. However, his versatility and proven track record make him an ideal fit for a team looking for a capable wideout to play opposite its top receiver next season. Hixon's not going to cost an arm or a leg, so it's worth taking a shot on a guy with his potential.