After a competitive first round of the NFL playoffs, this past weekend’s divisional round got wild and crazy. The Baltimore Ravens, unstoppable en route to a 14-2 record, were blown out at home by a nine-win Tennessee Titans team. The San Francisco 49ers looked like Super Bowl champs in a 27-10 win over the Minnesota Vikings. Aaron Rodgers was sharp in leading the Green Bay Packers past Russell Wilson and the Seattle Seahawks. And, let’s face it, the Kansas City Chiefs’ 51-31 win over the Houston Texans, in which they rallied from a 24-0 first-half deficit, was one of the greatest comebacks and greatest chokes in NFL playoff history.

The divisional round is often the best of the postseason, and even though two of the games were lopsided, this year it was exceptional as well as educational. It has been said that the NFL is a copycat league, and here are four big lessons other teams can take away from this season’s conference finalists: the 49ers, Packers, Chiefs and Titans.

Sometimes it’s okay to spend big in free agency.

Under previous general manager Ted Thompson, the Packers were known for avoiding free agent signings at all costs, and in doing so, they earned a reputation for avoiding the pitfalls of other teams that overpaid for star players who didn’t pay off.

That changed in a big way this offseason under new GM Brian Gutekunst, and the Packers proved that a team can succeed by participating in free agency — and, yes, maybe even overpaying a bit. The Packers went 4 for 4 in free agency, and it helped them advance to the NFC title game. Outside linebackers Za’Darius Smith and Preston Smith combined for 25½ sacks, and they added four in the victory over the Seahawks. Safety Adrian Amos was a Pro Bowl alternate. Billy Turner started at guard.

Sure, the Smiths’ contracts cost $28.2 million, but now that looks like a bargain. Maybe it looked like an overpay at the time, but the Packers got maximum value. Particularly with how front-loaded most free agent deals are, teams can be a little more aggressive in signing players to large contracts if they think it will translate to an on-field impact.

Quarterback play still matters most.

This was obvious all season as Lamar Jackson, Patrick Mahomes and Deshaun Watson changed the league’s hierarchy at the position.

But while Mahomes and Rodgers will headline the championship round, don’t overlook the importance of Jimmy Garoppolo and Ryan Tannehill to their teams. Garoppolo has been a steady, efficient presence after missing most of last year with a knee injury. Tannehill changed everything for Tennessee since replacing Marcus Mariota, providing the Titans with a balanced, potent offense that will give Kansas City trouble.

Chiefs Coach Andy Reid has almost always been at the helm of high-powered offenses, but Mahomes is on a different level. Their partnership will finally end Reid’s reputation as a coach who can’t win the big game.

As for Rodgers, he remains the top quarterback in the NFC, just ahead of Wilson and the New Orleans Saints’ Drew Brees. He is 36, but his skills haven’t declined in a significant way, as some have suggested. If there’s any blame for the Packers’ passing game, it should go to the pass-catching group beyond Davante Adams, who hauled in eight catches for 160 yards and two touchdowns in Sunday’s victory. The other wideouts caught just two balls for 19 yards.

A good running game can be a difference-maker.

The value of an NFL running back has changed and it’s a quarterback-driven league, but this year’s conference finalists — with a notable exception in Kansas City — have shown why a rushing attack can still be vitally important.

The success of Aaron Jones has given Green Bay a much more balanced offense. For the 49ers, who the running back is doesn’t seem to matter. Tevin Coleman, Raheem Mostert and Matt Breida have all starred in Coach Kyle Shanahan’s rushing offense, which ranked second in the league despite not having a mobile quarterback. The Packers, who aren’t great at stopping the run, will have their hands full trying to diagnose Shanahan’s running attack.

But there might not be a more unique rushing talent in the league than Titans running back Derrick Henry. At 6-foot-3 and 247 pounds, he is a wrecking ball with breakaway speed who has destroyed back-to-back playoff foes — both of whom possessed high-end defenses — in the New England Patriots and Ravens. He might cause defensive coordinators to slow the league’s trend of going smaller and faster on defense to better handle mobile quarterbacks and college-style play-calling; he’s simply too difficult to bring to the ground.

Offensive head coaches can benefit from loading up on defense.

The NFL continues to lean toward the offensive side of the ball with head-coaching hires, and three of the four conference finalists feature coaches with an offensive background. But what has been clear for all three of those teams — the Chiefs, 49ers and Packers — is that they’ve found success by investing heavily in defensive talent, often counting on their play-calling ability to get the most out of their offensive players.

The 49ers have five first-round draft picks in their defensive line rotation, with this year’s No. 2 pick, Nick Bosa, and offseason trade pickup Dee Ford forming the edge-rushing duo that made that defense elite. The offense is getting by with modest talent at wide receiver and running back — although star tight end George Kittle helps with that as well.

The Packers not only signed the Smiths at edge rusher and Amos at safety, but they invested both of their first-round picks on defensive players (edge rusher Rashan Gary and safety Darnell Savage Jr.) while ignoring their glaring need for a No. 2 wide receiver. The Chiefs certainly haven’t shied away from adding offensive talent under Reid, but their biggest offseason acquisitions — defensive end Frank Clark and safety Tyrann Mathieu — were blue-chip, high-priced defenders.

Around the NFL

— The odds of Tom Brady leaving New England continue to grow. Some people around the league wouldn’t be surprised if Carolina Panthers owner David Tepper might be interested. The Indianapolis Colts and Los Angeles Chargers are also logical options.

What’s clear is there is a certain maximum salary number the Patriots would go to re-sign Brady. It’s not yet certain what that will be, but if it’s $25 million to $27 million, Brady might take the chance to get into the $30 million plus range with another teams.

— Josh McDaniels figures to be a head coach at some point. But you have to wonder if his pulling out of a deal to coach the Indianapolis Colts two offseasons ago makes him a tougher sell. Twelve teams, including the Cleveland Browns twice, made coaching changes over the past two years, but McDaniels remains with the Patriots.

— The Texans’ devastating loss to Kansas City could lead to changes. Defensive coordinator Romeo Crennel, 72, might not be back, and some are writing that it’s time to move on from Coach Bill O’Brien.

After the firing of general manager Brian Gaine, O’Brien has been making the personnel decisions. He went all in on this year, which was somewhat justified as Houston won the AFC South for the fourth time in five years, but the Texans will pay a price for it moving forward. They don’t have first-round draft picks the next two years, and they are missing a third-rounder next year and a second-rounder in 2021. In other words, they have just two picks in the top three rounds of the next two drafts.

Watson stood up for O’Brien after the game, but the fact remains he has two playoff wins in six games. O’Brien’s decision to kick a field goal on fourth and one from the 13-yard line when up 21-0 and his horrible fake punt call will stick with fans for a while.

— The 2019 draft wasn’t considered strong for wide receivers, but several second-round picks have proved that wrong. Look at the playoff teams. Deebo Samuel has 802 receiving yards for the 49ers and has been incredible on jet sweeps and quick play-calls from Shanahan. A.J. Brown helped the Titans get to the AFC title game with 60 catches for 1,051 yards. DK Metcalf was a stud for the Seahawks with 58 catches for 900 yards. And Mecole Hardman was a Pro Bowl returner selection and a dangerous weapon for the Chiefs.