The end of the year is a time to reflect—on what you’ve learned, and on how you’d like to change as you move forward. It’s no different in the NFL. Each season teaches us lessons about how teams should build their rosters and coaching staffs. So consider this list a collective New Year’s resolution for the teams that are in need of some serious introspection.

1. The days of fixating on what quarterbacks can’t do should be over.

Lamar Jackson’s success with the Ravens will undoubtedly inspire teams to try to find “the next Lamar Jackson.” Yeah … good luck with that. Baltimore’s offense has thrived because Jackson is a special runner and coordinator Greg Roman’s scheme is unlike any other in the NFL, but teams that try to replicate that formula are doomed to fail.

The lesson from Baltimore’s experience with Jackson is that the organization saw an exceptionally talented quarterback, believed in that talent, and built a system designed to maximize it. Jackson wasn’t some small-school prospect who Baltimore discovered by chance. He wasn’t even a supremely gifted, but hard to evaluate anomaly like Patrick Mahomes. Jackson won the goddamn Heisman Trophy. He was the best player in college football for an entire season. Yet instead of focusing on all of his exceptional traits, every other QB-needy team decided to fixate on what they believed Jackson couldn’t do.

It’s not quite as damning, considering he was drafted 12th overall, but it’s similar to what happened with Deshaun Watson in 2017. Watson may not have won the Heisman, but he played in two consecutive national championship games, knocked off Alabama in the second, and finished his career as one of the most productive college quarterbacks of all time. Then, when draft time rolled around, the Bears decided that Mitchell Trubisky—he of 13 career collegiate starts—was a better choice to lead their franchise. All Watson has done since is carry the Texans to two playoff berths in a row and develop into one of the most exhilarating players in the NFL.

The message here isn’t that teams should ignore a prospect’s glaring weaknesses. It’s that when a player is showing you—through elite production against the best teams in the country—that he’s great, maybe you should believe him. Quarterback evaluation is obviously more complex than that, but in the cases of Watson, Mahomes, and Jackson, teams made it more convoluted than needed. Lamar Jackson was one of the best college football players of the decade, and the Ravens have given him the space to show everyone why. And they may just win a Super Bowl because of it.

2. Defenses that are built back to front may have a better shot against modern offenses.

Back in May, Pro Football Focus data scientists Eric Eager and George Chahrouri published a study that focused on the impact of coverage and pass rush on a team’s defense. They found that a defense’s coverage ability had a stronger correlation to success than its ability to rush the passer. At a time when dominant edge rushers are considered more valuable than any players but quarterbacks, their conclusion ran somewhat counter to conventional wisdom. But man, did this season provide a lot of evidence in their favor.

Arguably the two best teams in the AFC—Baltimore and New England—have constructed their defenses with this value system in mind. Both teams allocated a minimal amount of their 2019 salary cap to edge rushers and allowed high-priced players like Trey Flowers and Za’Darius Smith to walk in free agency. The Ravens used their extra resources to sign free safety Earl Thomas and absorb Marcus Peters’s contract in an October trade. With Thomas and Peters joining Jimmy Smith and slot cornerback Marlon Humphrey, the Ravens now have four former first-round picks in their starting secondary.

New England didn’t make any headline-grabbing additions this offseason, but Defensive Player of the Year favorite Stephon Gilmore and safety Devin McCourty are two of the highest-paid players at their respective positions. Baltimore and New England have constructed the deepest, most versatile secondaries in the NFL, and those units allow both teams to execute schemes few other defensive coordinators would even attempt.

The Ravens have sent heat more often this season than any other team. According to John Shirley of Sports Info Solutions, Baltimore entered Week 16 with an absurd 44 percent blitz rate. New England ranked ninth, at 29 percent, but the Patriots have weaponized all-out blitzes with zero coverage to great effect all season. All that blitzing has allowed both teams to consistently create pressure without much elite edge-rushing talent. And while the Bills don’t blitz nearly as often, they’re another prime example of a great pass defense that relies on an excellent secondary. There are challenges to building a defense this way—year-to-year performance among DBs has a much higher variance than quality edge rushers. And teams like the Niners and Steelers show that a great pass rush can still carry a defense. But some of the most effective units have exemplified the kind of impact a back-to-front construction can have when things go right.

3. A team’s most important personnel moves often come after free agency and the draft.

Arguably the two biggest additions Seattle made to its defense this season happened after the team already broke training camp. General manager John Schneider’s late August trade for Jadeveon Clowney gave the Seahawks the game-wrecking player they needed up front for the low, low price of a third-round pick. And in October, Schneider solidified the back end of his defense by trading for Lions safety Quandre Diggs, who’s made a series of game-changing plays since his arrival.

Baltimore got its own playmaking defensive back by trading for Peters around the deadline, and his arrival helped fill out one of the league’s best secondaries. Emmanuel Sanders is another pass-catching weapon for the 49ers who fits perfectly within head coach Kyle Shanahan’s offense. And the Patriots signed All-Pro candidate Jamie Collins to a one-year, $3 million deal in the middle of May—long after the league’s more expensive free agents had inked their monster deals.

As the NFL has become more of a year-to-year league, teams in the hunt are much more lucky to become buyers around the deadline. But Seattle made the Clowney move long before Schneider knew whether his team would be a contender. There’s always value to be found in players on expiring contracts, guys who weren’t drafted by their current front-office regimes, and effective starters who were relegated to the bench because of a scheme change. The best GMs are constantly trying to find undervalued assets, and pick-for-player trades continue to be one of the most effective means of finding those assets.

4. NFL coaching still dictates who succeeds and who fails.

The chasm between good coaching and poor coaching isn’t unique to 2019, but boy, was it on full display with some of the league’s most disappointing teams. The Browns probably weren’t deserving of all the preseason love they received (I’m as guilty as anyone), but there’s no denying the talent on this roster. Baker Mayfield looked like a budding star as a rookie last season. Odell Beckham Jr. and Jarvis Landry gave Cleveland a potent one-two punch at wide receiver. Nick Chubb is one of the most physically gifted backs. And the defense is stocked with excellent players, especially up front. None of that stopped the Browns from being borderline unwatchable. Mayfield’s regression in his second season is startling. It’s possible that his year-one success was a mirage, but there are plenty of smart people around the league who remain steadfast Mayfield believers. I wrote in detail about the issues with Cleveland’s offense earlier this season, and while Mayfield certainly deserves some of the blame, his coaching staff rarely did him any favors.

The Cowboys had considerably more success on offense under head coach Jason Garrett and first-year coordinator Kellen Moore—they entered Week 16 ranked second in Football Outsiders’ DVOA. But after Sunday’s loss to Philadelphia, Garrett’s team is 7-8 and in real danger of missing the playoffs. The Cowboys were a prime regression candidate entering the season, given an expected decline on defense and worse luck in close games, but that was before this team exhibited its offensive ceiling. With Ezekiel Elliott and Amari Cooper in the fold all season, and Dak Prescott playing at such a high level, these games shouldn’t have been that close in the first place. Dallas has built one of the best rosters, and yet another year is about to pass with nothing to show for it.

Imagine what a coach like Kyle Shanahan or Sean Payton could do with Dallas’s roster. Shanahan has done a masterful job at the helm in San Francisco this year. The Niners entered Week 16 ranked seventh in passing DVOA, despite a lack of quality receiving talent and some up-and-down play from Jimmy Garoppolo. Shanahan’s ability to scheme his team to big gains has been on full display. The same goes for Payton, who has the Saints in position for a first-round bye, even though Drew Brees missed five and a half games with a thumb injury. And I haven’t even brought up John Harbaugh, whose vision and humility has turned the Ravens into a football-nerd dream. Great coaching has always mattered, but the gap between the league’s best coaches and its worst ones was stark this season.

5. Adding or promoting the right assistant coaches can dictate a team’s entire season.

The Ravens’ run to the top seed in the AFC wouldn’t have happened without Lamar Jackson, but it wouldn’t have been possible without offensive coordinator Greg Roman, either. At this time last year, Roman was the tight ends coach in Baltimore. Now, he’s the hottest head-coach candidate because of the work he’s done turning the Ravens into the most potent offense in football. In Minnesota, the Kevin Stefanski–Gary Kubiak combination has turned the Vikings offense into one of the most explosive units—and more than justified Kirk Cousins’s $84 million deal in the process. This is Brian Daboll’s second year at the helm of Buffalo’s offense, but this season he’s shown the impact he can have with Josh Allen and the passing game. And Kansas City’s decision to replace Bob Sutton with Steve Spagnuolo has helped take the Chiefs defense from a liability to a league-average unit.

Switching coordinators with a reliable head coach at the wheel is the most obvious upgrade a team can make to a lagging unit, but contenders have benefited from subtler moves, as well. Robert Saleh has been the Niners’ defensive coordinator for the entirety of Shanahan’s tenure in San Francisco, but the addition of passing game coordinator Joe Woods and defensive line coach Kris Kocurek has played a big role in the Niners’ defensive turnaround. Big-time draft picks and high-priced free agents garner most of the offseason headlines, but quieter coaching moves can have the same sort of impact come playoff time.