Roster building through free agency is all too often a recipe for disappointment in the modern NFL. As the Raiders, Giants, Redskins and Bills have proven this year, though, organizations that once struggled to post winning records can use the talent infusion as a springboard to a run at the postseason.
Here's our look at the best free-agent success stories of the 2016 season:
1) Zach Brown and Lorenzo Alexander, LB, Buffalo Bills: Signed to a one-year, $1.25 million contract, Brown was supposed to play behind rookie Reggie Ragland. Pressed into service due to Ragland's ACL tear in training camp, the former Titans second-round pick has finally made the leap, flirting with the league lead in tackles all season long. Brown is also tied for first in Pro Football Focus' "stops" metric, which identifies a play that constitutes a failure for the offense. His 18-tackle effort in the Week 4 shutout at New England remains one of the most impressive performances of the season.
2) Kelechi Osemele, OG, Oakland Raiders: For all of the well-deserved hype in Dallas, it's Oakland's offensive line that is the premier pass-protecting unit in the league. Derek Carr has been sacked just 11 times this season, the fewest of any full-time starting quarterback. Osemele has been just as dominant in the ground attack, paving the way for the Raiders' three-headed backfield of Latavius Murray, DeAndre Washington and Jalen Richard. While shaky offensive-line play has sunk several would-be contenders this season, Osemele's crew has helped vault Oakland to the top of the AFC West.
3) Eric Weddle, S, Baltimore Ravens: When the Chargers neglected to honor Weddle's wish of retiring with the organization, he defected to Baltimore with a Steve Smith-sized chip on his shoulder. Following Smith's lead, he's playing at an All-Pro level in his twilight years. With Weddle anchoring an improved secondary, the Ravens rank first in run defense, second in total defense and second in third-down percentage this season.
4) Alex Mack, C, Atlanta Falcons: A perennially anemic offensive line eventually led to Mike Smith's dismissal in Atlanta. As many resources as Thomas Dimitroff sunk into blocking, the Falcons simply couldn't protect Matt Ryan or open consistent holes in the ground attack. That changed when Kyle Shanahan brought his zone-blocking scheme to town in 2015. The offense didn't reach its potential, though, until Mack arrived as a stabilizing force in the pivot this season. The Falcons have improved from 21.2 to 32.0 points per game, dramatically increasing their efficiency across the board as the league's most dangerous attack. Mack is a lock for his fourth career Pro Bowl selection.
5) Janoris Jenkins, CB, New York Giants: Consider Jenkins the avatar for a successful Giants free-agent haul that included defensive ends Olivier Vernon and Jason Pierre-Paul, as well as run-stuffer Damon "Snacks" Harrison. While Ben McAdoo's offense has yet to score 30 points in a game after accomplishing the feat six times a year ago, the defense has driven New York's dramatic turnaround. Led by Jenkins and burgeoning All-Pro safety Landon Collins, the secondary is the most improved unit on the team. "I think you'd be hard-pressed to find a corner in this league playing better than (Jenkins) is," Jeff Fisher raved before his Rams squared off with the G-Men in London a month ago.
6) Lamar Miller, RB, Houston Texans: It's incredible that Bill O'Brien's squad is hanging onto first place in the AFC South with a 6-4 record as the quarterback threatens to sabotage the entire operation. While Brock Osweiler has been an unmitigated disaster under center, Miller has kept the offense afloat as the NFL's fifth-leading rusher. Underutilized in Miami, Miller has churned out tough yardage behind a subpar offensive line, mixing in enough big plays to set Osweiler up for the occasional red-zone opportunity. He's on pace for 307 carries and 1,318 rushing yards, numbers that would shatter his previous career highs of 216 and 1,099.
7) Nigel Bradham, LB, Philadelphia Eagles: After a slow start to the season, Jim Schwartz's hand-picked weak-side linebacker has come on strong with nearly 10 tackles per game over the past six weeks. Bradham also has led his new team's turnaround in tight-end defense, holding his offensive counterparts to two catches or fewer in half of the Eagles' 10 games. This is the NFL's most improved scoring defense, allowing just 18.6 points per game (and a league-best 9.5 at home). Outside of leading tacklers Bradham and safety Rodney McLeod, the defensive personnel is largely unchanged from last year's unit that surrendered 26.9 points per game.
8) Rishard Matthews, WR, Tennessee Titans: Remember when Matthews was losing snaps to Andre Johnson in early October? Since then, Johnson has retired while Matthews has emerged as Marcus Mariota's most reliable wideout, averaging nearly a touchdown per week in the NFL's hottest offense. The wide receiver's answer to Lamar Miller, Matthews was never properly valued in four years with the Dolphins. He's on pace to shatter career highs across the board in Nashville. Jordy Nelson, Mike Evans and Antonio Brown are the only receivers with more touchdowns this season.
10) Vernon Davis, TE, Washington Redskins: Davis might not be more valuable than several players left out of the top 10, but he's perhaps the most surprising. Written off as a washed-up former Pro Bowler after flaming out in San Francisco and Denver last season, Davis has been a godsend as Jordan Reed's sidekick in his return home to the nation's capital. The Redskins' rise to the top of the league's offensive charts has coincided with Davis' elevated role. Beating linebackers and safeties down the seam, the 32-year-old tight end averaged 72 yards over a four-game span from Week 6 to Week 10. The futures of impending free agents DeSean Jackson and Pierre Garcon might be up in the air, but the future of this offense is in fine shape with Cousins, Reed, Davis, Rob Kelley, Jamison Crowder and 2016 first-round draft pick Josh Doctson.
More notable free-agent success stories (in alphabetical order): LeGarrette Blount, RB, New England Patriots; Anquan Boldin, WR, Detroit Lions; Brandon Brooks, OG, Philadelphia Eagles; Jahri Evans, OG, New Orleans Saints; Brent Grimes, CB, Tampa Bay Buccaneers; Damon Harrison, DT, New York Giants; Casey Hayward, CB, San Diego Chargers; Akiem Hicks, DE, Chicago Bears; Richie Incognito, OG, Buffalo Bills; Bruce Irvin, LB, Oakland Raiders; Charles Johnson, DE, Carolina Panthers; Marvin Jones, WR, Detroit Lions; Rodney McLeod, S, Philadelphia Eagles; Donald Penn, OT, Oakland Raiders; Nick Perry, LB, Green Bay Packers; Jason Pierre-Paul, DE, New York Giants; Bilal Powell, RB, New York Jets; Perry Riley, LB, Oakland Raiders; Craig Robertson, LB, New Orleans Saints; Mohamed Sanu, WR, Atlanta Falcons; Josh Sitton, OG, Chicago Bears; Matt Slauson, C, San Diego Chargers; Olivier Vernon, DE, New York Giants; Mike Wallace, WR, Baltimore Ravens.