NFL teams build the bulk of their rosters right through the draft, opting to find the final pieces in free agency or via the trade market.
This isn't Major League Baseball, where you can throw around contracts worth hundreds of millions without having it count against the salary cap. Thankfully, the NFL has a salary cap that forces teams to spend their money carefully and wisely. You cannot buy a Super Bowl championship the way baseball teams can buy a World Series.
But the bulk of Super Bowl champions and powerhouse teams need to spend every now and then in order to put the final touches on their rosters. Would the San Francisco 49ers and Dallas Cowboys have Super Bowls in the '90s if neither signed Deion Sanders? Where would Brett Favre and the '90s Green Bay Packers go if Reggie White never left the Philadelphia Eagles? Sometimes, it's necessary to throw tens of millions at a star player.
You can take a look at recent Super Bowl champions like the Seattle Seahawks, New England Patriots, Denver Broncos and Eagles. They found the bulk of their core players right through the draft, but the final pieces were added in free agency. You'll see those "pieces" on this list.
But on the flip side, some teams get too greedy and excited - throwing money around like there's no tomorrow. Spoiler alert: It totally backfires on them and they regret it forever.
Here's a look at the 10 worst NFL free agent signings since 2010, and 10 that paid off big time.
20 Worst: Jets Sign Eric Decker
Eric Decker enjoyed a pair of productive seasons with Peyton Manning as a member of the Denver Broncos. He caught at least 85 passes in the 2012 and '13 seasons, notching over 1,000 receiving yards and double-digit touchdowns in each.
The New York Jets were looking for a new pass-catcher to work around Geno Smith, so they gave Decker a five-year contract worth $36.25 million. Decker had productive seasons for the Jets in 2014 and '15, even registering 1,027 yards in the latter year.
But a shoulder injury limited Decker to just three games in the 2016 season, and the Jets opted to release him in the ensuing offseason. The Jets simply didn't get their money's worth on Decker, who was only lived up to that contract in the 2015 season.
19 Paid Off: Patriots Sign Darrelle Revis
The New England Patriots were looking for that final piece in their secondary, and Bill Belichick was losing Aqib Talib in 2014 free agency. Despite a heated past with former New York Jets All-Pro cornerback Darrelle Revis, Belichick opted to give his former enemy a one-year deal worth $12 million.
Revis had one of his best seasons as a cornerback and transformed New England's defense into one of the NFL's best. He earned another Pro Bowl nod and locked down the opponent's top wide receiver for the bulk of the season.
Revis was also key in helping the Patriots win Super Bowl XLIX over the Seattle Seahawks, too. The Super Bowl ring was the final thing missing on Revis' career, and he finally earned it by signing with the enemy. Poor Jets fans.
18 Worst: Colts Sign Andre Johnson
The Indianapolis Colts reached the 2014 AFC Championship Game, losing to the New England Patriots in blowout fashion. Even though it was clear that the Colts' defense and ground game were the main problems, the front office thought otherwise.
They opted to spend the money and draft picks on offense instead, even though Andrew Luck didn't require reinforcements. Their biggest move was giving Pro Bowl wideout Andre Johnson a three-year contract worth $21 million, but it turned out to be one giant waste of money.
Johnson only caught 41 passes for 503 yards and four touchdowns. Worse yet, the Colts didn't even make the playoffs, and Johnson's former team in the Houston Texans wound up winning the AFC South instead. The Colts released Johnson after the 2015 season, not getting anything big out of a player who should wind up in the Hall of Fame anyway.
17 Paid Off: Broncos Sign DeMarcus Ware
The Dallas Cowboys that that Pro Bowl pass rusher and future Hall of Famer DeMarcus Ware was nearing his prime, so they released him in the 2014 offseason. The Denver Broncos jumped on the opportunity and gave Ware a three-year contract worth $30 million, and it turned out to be a huge steal for John Elway.
Ware turned back the clock and had a productive first season in Denver, registering 10 sacks and a pair of forced fumbles. A year later, he registered 7.5 sacks and was instrumental in helping the Broncos win Super Bowl 50 over the Carolina Panthers - led by MVP Cam Newton.
Ware retired after the 2016 season, having been named to a pair of Pro Bowls during his tenure in the Mile High City. He capped off his Hall of Fame career by leading Denver to a Super Bowl. The $30 was so totally worth it.
16 Worst: Eagles Sign DeMarco Murray
DeMarco Murray won the rushing title with the Dallas Cowboys in 2014, but Jerry Jones and the front office were smart to not overpay a player who was simply a product of a stacked offensive line.
Looking to steal a superstar away from their NFC East rivals, the Philadelphia Eagles gave Murray a five-year contract worth $42 million. The Eagles also signed former Charger Ryan Matthews, so the ground game was expected to take off.
Well, Murray turned out to be a massive bust in Philly. He averaged a woeful 3.6 yards per carry and had just 702 rushing yards and six touchdowns. The Eagles gave up on Murray and traded him to the Tennessee Titans in the offseason, forever ridding themselves of that one awful contract.
15 Paid Off: Bears Sign Julius Peppers
The Carolina Panthers decided not to retain Pro Bowl defensive end Julius Peppers after the 2009 season, but their loss turned out to be the Chicago Bears' gain. Peppers was signed to a massive six-year, $91.5 million contract, but he turned out to be worthy of every penny.
Peppers was a mainstay on the Chicago defense, helping them return to the postseason in 2010. Chicago even reached the NFC Championship Game, where they narrowly fell to the Green Bay Packers.
In his four years with the Bears, Peppers racked up 37.5 sacks and 10 forced fumbles. He was named to the Pro Bowl three times during his tenure in Chicago. So yeah, Peppers was absolutely worth all the money.
14 Worst: Dolphins Sign Mike Wallace
One of the fastest wide receivers the NFL has ever seen, Mike Wallace entered the 2013 offseason as one of the most sought-after free agents. He was a two-time 1,000-yard receiver and had a knack for making the big plays.
Looking to build around quarterback Ryan Tannehill, the Dolphins gave Wallace a five-year contract worth $60 million. Wallace was eh-okay during his two years in Miami, finishing with 836 and 930 yards over his two seasons there. The Dolphins gave up on Wallace after failing to live up to his contract, and he was dealt to the Minnesota Vikings in the 2015 offseason.
13 Paid Off: Falcons Sign Alex Mack
After another disappointing season in 2015, the Atlanta Falcons went on a major offseason spending spree. Their top signing was Cleveland Browns center Alex Mack, who inked a five-year contract worth a bargain $45 million.
Mack solidified Atlanta's pass protection for Matt Ryan, and the ground game reached another level under the dynamic duo of Devonta Freeman and Tevin Coleman. Mack was instrumental in helping Atlanta reach Super Bowl LI, where they nearly beat the New England Patriots.
Mack has been named to the Pro Bowl in each of his first three seasons with the Falcons, and there's no way this offense plays at a high level without him. This will go down as the best free agent signing that GM Thomas Dimitroff ever made, plain and simple.
12 Worst: Bears Sign Mike Glennon
Mike Glennon spent one season as the Tampa Bay Buccaneers' starter (2013), but he'd eventually be demoted as a backup to Jameis Winston, who was drafted first overall in 20115.
Glennon was a decent backup in Tampa Bay, but the Chicago Bears saw something special in him. During the 2017 offseason, the Bears gave Glennon a three-year contract worth a whopping $45 million.
The Bears would later move up to draft Mitch Trubisky, who didn't need long to wait long before taking over as the starter in his rookie year. Glennon had four touchdowns in five picks for the Bears in 2017, and they opted to release him in the ensuing offseason.
11 Paid Off: Broncos Sign Emmanuel Sanders
The Broncos lost Eric Decker to the New York Jets in free agency, so Elway looked for a cheaper option. He somehow got former Pittsburgh Steelers wideout Emmanuel Sanders on a bargain three-year, $15 million contract. And boy, did it ever pay major dividends.
Sanders and Peyton Manning made a remarkable connection right away, with the former catching 101 passes for 1,404 yards and nine touchdowns in 2014. Sanders once again hit the 1,000-yard mark in 2015 and '16, and remains one of the top playmakers on the Denver offense.
Sanders was Denver's best player on offense during their Super Bowl 50 season. He was also named to the 2014 and 2016 Pro Bowl. And the Broncos landed this guy for a mere $15 million? Just more magic from Elway.
10 Worst: Jets Sign Darrelle Revis
The New England Patriots made the right call on a) signing Darrelle Revis in 2014 and b) opting to let him walk in 2015 free agency. Revis signed a five-year, $70 million contract with the New York Jets in the offseason, returning to the team he had played for from 2007 to 2012.
Revis had another Pro Bowl season in 2015, registering nine passes defended and five interceptions while leading the Jets to a 10-5 record. However, Revis suddenly unraveled in his 2016 age-31 season, getting burned big time in coverage and admitting that he was slowing down.
The Jets released Revis after the 2016 season, getting very little out of their $70 million investment. To make matters worse for New York, the Patriots would win another Super Bowl without Revis. So much for a double whammy move.
9 Paid Off: Ravens Sign Eric Weddle
One of the game's elite safeties for over a decade now was rewarded by the Baltimore Ravens with a four-year, $26 million deal in the 2016 offseason. Weddle was coming off another productive season for the San Diego Chargers, and he wound up being one of the top free agent signings under the great Ozzie Newsome.
Weddle has endured three great seasons with the Ravens, earning a Pro Bowl nod in 2016, '17 and '18. The Ravens defense has been the NFL's best this season, and Weddle has played a key role in that.
The Ravens somehow got a future Hall of Famer at such a discounted price, but they won't complain about it. All that's missing on Weddle's resume is a Super Bowl ring, but we shouldn't really discount his chances of getting one before he hangs them up.
8 Worst: Cardinals Sign Sam Bradford
After missing out on the Kirk Cousins sweepstakes, the Arizona Cardinals went with a backup plan and gave veteran Sam Bradford a two-year contract that could have been worth up to $20 million per season.
The Cardinals would later trade up to draft Josh Rosen, so that made the Bradford signing even more questionable. Throw in the fact that this was an inconsistent and oft-injured signal-caller, and the contract looked like a mess from the beginning.
Bradford struggled big time in his three games for the Cardinals, and the decision was made to release him mid-season. Bradford went unsigned the rest of the season, and he'll likely have to stay on as a backup for the rest of his career.
7 Paid Off: Seahawks Sign Cliff Avril
Even though he was one stud of a pass rusher for the Detroit Lions, Cliff Avril was always overlooked, thanks in large part to Ndamukong Suh's extreme dominance. But the Seattle Seahawks took note of Avril's talents and gave him a two-year, $13 million pact in the 2013 offseason.
The move was pure genius by GM John Schneider, who was looking to put the final touches on an elite defense led by the Legion of Boom - namely Richard Sherman, Earl Thomas and Kam Chancellor.
Avril had eight sacks in 2013 and helped the Seahawks defeat the Denver Broncos XLVIII, wreaking havoc on Peyton Manning's record-setting offense. The Seahawks would reach another Super Bowl with Avril the following year. He was named to the 2016 Pro Bowl and finished with 34.5 sacks over his five years with Seattle.
6 Worst: Saints Sign Jairus Byrd
The New Orleans Saints owned one of the NFL's best defenses in the 2013 season, so it made perfect sense to give Pro Bowl safety Jairus Byrd a six-year, $56 million in the 2014 offseason.
Byrd was among the game's elite safeties during his days with the Buffalo Bills, due to his incredible ball-hawking skills and slick coverage. Adding Byrd to an elite defensive unit was supposed to do wonders for New Orleans.
Byrd suffered a season-ending knee injury during the 2014 campaign, and he was never able to regain his Pro Bowl form in 2015 or '16. The Saints released Byrd after three years, ridding themselves of arguably the worst free agent signing in their history.
5 Paid Off: Seahawks Sign Michael Bennett
The Seattle Seahawks were building up a championship caliber team in 2012, led by Russell Wilson and the Legion of Boom defense. But Pete Carroll and GM John Schneider knew that a couple of reinforcements wouldn't hurt, so they gave Michael Bennett a one-year, $4.8 million deal in the 2013 offseason.
Bennett - who had spent bits of his rookie 2009 campaign in Seattle - suddenly emerged as a superstar. He became one of the league's elite pass rushers - registering at least seven sacks between the 2013 and '15 seasons.
Bennett's efforts helped Seattle defeat the Denver Broncos in Super Bowl XLVIII, and he got them back to the big game a year later. Bennett wound up being one of the final pieces of Seattle's puzzle, helping them win their first Super Bowl in history. The Legion of Boom simply doesn't dominate without Bennett's superb pass rushing game.
4 Worst: Texans Sign Brock Osweiler
Brock Osweiler only started seven games for the Denver Broncos in the 2015 season, and he wound up losing his job in Week 17 to Peyton Manning. The latter retired after helping the Broncos win Super Bowl 50, and despite efforts from Elway to retain Osweiler, the 'Brockness Monster' wasn't interested.
The Houston Texans gave Osweiler a four-year, $72 million contract in the offseason, believing they had their new franchise starter. If only.
Osweiler only completed 59 percent of his passes for 15 touchdowns and 16 interceptions. He couldn't do much of anything on the Houston offense, and his pathetic showing in the playoffs was enough for the Texans to give up.
How desperate were they to get out of his contract? The Texans gave up second and sixth-round picks to the Cleveland Browns for taking on his contract. The Browns would release Osweiler before the 2017 season began.
3 Paid Off: Eagles Bring Back Nick Foles
Nick Foles pondered retirement after a disappointing 2015 season with the St. Louis Rams, but Kansas City Chiefs head coach Andy Reid convinced him to join the team and backup Alex Smith. Foles rediscovered his love of football and saw some playing time during the 2016 season, but the Chiefs opted not to bring Foles back in 2017.
Foles would sign a two-year contract to backup second-year signal-caller Carson Wentz, and it wound up being a franchise changing move. You know the rest, as Wentz tore his ACL in the midst of an MVP caliber season, forcing Doug Pederson to turn to Foles the rest of the way.
Foles played at an MVP level and helped the Eagles lock up the first seed in the NFC. He the guided Philly to a surprise Super Bowl LII appearance against the defending champion New England Patriots.
Well, Foles completed 28 passes for 373 yards and three touchdowns, leading the Eagles to their first Super Bowl championship in franchise history. Foles was named Super Bowl MVP and cemented his legacy as a Philadelphia sports hero. What a move it was by Howie Roseman to give Foles another chance. It only produced a Super Bowl championship.
2 Worst: Eagles Sign Nnamdi Asomugha
Once the NFL lockout ended in the summer of 2011, Oakland Raiders cornerback Nnamdi Asomugha began fielding offers from a handful of teams - including the Dallas Cowboys and New York Jets.
But when all was said and done, the Philadelphia Eagles gave Asomugha a five-year contract worth $60 million. Backup quarterback Vince Young infamously called Philly 'The Dream Team' after also adding Cullen Jenkins and Jason Babin.
Asomugha couldn't fit into the Eagles' defensive schemes and turned out to be a major flop. He struggled to stay healthy and went from an elite shutdown corner to an afterthought. The Eagles released Asomugha after the 2012 season, moving on from one of the worst free agent signings ever.
1 Paid Off: Broncos Sign Peyton Manning
After mutually parting ways with the Indianapolis Colts in the 2012 offseason, Peyton Manning became one of the most sought-after free agents in NFL history. At least a half dozen teams seriously pursued the future Hall of Famer, but it was Elway and the Broncos who won the Manning sweepstakes - inking him to a five-year, $96 million contract.
Manning turned out to be worth every single penny. He led the Broncos to AFC West division titles in each of his four seasons there. Manning guided the Broncos to AFC Championship victories in 2013 and '15, too. He won the MVP award in the former year and retired after helping the Broncos win Super Bowl 50.
Division titles. Conference titles. Broken records. An MVP award. And a Super Bowl? Manning was absolutely worth the $96 million. No doubt about it.