Your guide to the NFL offseason: 20 things you might have missed

Greenberg: NFL can't make everyone happy with anthem policy (1:56)

Richard Jefferson and Mike Greenberg react to the NFL's latest attempt to address the issues surrounding the anthem. (1:56)

It has been 165 days since the Philadelphia Eagles won Super Bowl LII. Fortunately for us all, this long and occasionally maddening NFL offseason is nearly over.

If you tuned out after the confetti fell, here are 20 of the most important things you missed.

1. Anthem policy imposed -- then retracted

Owners wanted desperately to remove anthem protests from public discussion, but they were starkly divided on how to do it. The plan they announced in May -- players could either stand for the anthem or go to the locker room -- resulted in ongoing public mockery as well as an NFL Players Association grievance. On Thursday night, the NFL and NFLPA agreed to put the plan at a "standstill" while trying to craft a more amenable approach. The implicit deadline is the start of the preseason.

2. Concussion fallout

The league's data service reported 291 concussions for 2017, which was the highest total on record. That revelation prompted the NFL's chief medical officer, Dr. Allen Sills, to declare a "call to action" in February. Sills' goal was to implement data-driven rules and policies that would lower the concussion numbers immediately.

3. New helmet rule

Owners scrambled at their late-March meetings to approve this rule, an unscheduled response to data that showed a concussion resulting from one of every two hits involving helmet-to-helmet collisions. It is now a 15-yard penalty, with a possible ejection in flagrant cases, for any player to lower his helmet to initiate contact with an opponent. League officials promoted it as a game-changer, but its true impact rests with how it is officiated.

4. New kickoff rule

After learning that concussions were five times as likely to occur on kickoffs as on other plays, owners considered eliminating the kickoff altogether. Instead, they approved a one-year experiment devised by a group of special-teams coaches that makes the kickoff more like a punt. They hope that alignment shifts, new blocking rules and elimination of a running start for cover men, among other changes, will minimize high-speed collisions. Late implementation has led to concern among officials and the possibility of additional tweaks this summer.

5. Helmet restrictions

For the first time, the NFL and NFLPA have banned certain helmet models they deemed through testing to be outdated or underperforming. Six styles were banned immediately and four others must be phased out by 2019.

6. Training camp drills targeted

NFL data showed a 73 percent jump in concussions during early training camp drills in 2017 compared to 2016, another focus of Sills' initiative. Teams have been supplied with detailed, customized data to reflect how and when each of their 2017 camp concussions occurred. No drills have been banned, but the league is encouraging teams to adjust on their own.

7. Four referees retired

Circumstances conspired to create the highest level of referee turnover in NFL history. Ed Hochuli and Jeff Triplette retired shortly after the season. Then, in June, NBC lured Terry McAulay to its Sunday Night Football booth. CBS soon hired Gene Steratore. Indeed, the NFL's complicated rule book means every league broadcaster now employs a rules expert. ESPN hired Triplette, per a source. The four new referee names you need to know: Shawn Hochuli (Ed's son), Alex Kemp, Shawn Smith and Clay Martin.

8. New catch rule

The concussion-related rule changes overshadowed what would otherwise have been the biggest story of the offseason. Players no longer are required to "control the ball throughout the process of going to the ground." Instead, a catch is defined as controlling the ball in bounds with the ability to perform a football move such as taking a third step -- whether or not the receiver is going to the ground. In other words, if Dez catches it in 2018, he'll actually have caught it. The challenge for officials now is to identify football moves. The hope is that they'll know it when they see it.

9. Thursday nights move to Fox

In a five-year deal that will net an average of $660 million annually, the NFL awarded its 13-game Thursday night package to Fox. The decision came shortly after the league acknowledged a higher injury rate for Thursday night games in 2017 compared to other days. Commissioner Roger Goodell judged the rise "not even statistically significant." Meanwhile, Amazon renewed its deal to stream Thursday night games to its Prime customers.

10. Panthers were sold

Investor David Tepper, a former minority owner of the Pittsburgh Steelers, purchased the Carolina Panthers from franchise founder Jerry Richardson for a league-record $2.275 billion. Richardson put the team up for sale shortly after Sports Illustrated published a report detailing sexual and racial misconduct in the workplace. An independent investigation led the NFL to fine Richardson $2.75 million.

11. Eagles were disinvited from White House

President Donald Trump canceled the traditional ceremony for the Super Bowl champions in May after learning that only a handful of team members planned to attend. The incident further raised tensions between the league and Trump, who continues to criticize players who protest during the anthem as well as the league and its owners for failing to stop them.

12. Players highlighted goodwill efforts

Amid Trump's narrative, players -- as they always do -- devoted part of their offseason to community service. Among many initiatives was that of Eagles safety Malcolm Jenkins and defensive end Chris Long, who worked to address mass incarceration.

13. Eric Reid filed a collusion grievance

The former San Francisco 49ers safety -- ranked No. 20 on ESPN's list of the top 100 free agents of 2018 -- has yet to sign with a team. He formally accused NFL owners in May of colluding against him because of his close association with quarterback Colin Kaepernick, another unsigned free agent who also has filed collusion charges. Reid and Kaepernick have been the most visible players to protest during the national anthem.

14. Kirk Cousins landed a fully guaranteed contract

After sitting tight for two years as the Washington Redskins' franchise player, Cousins was a rarity on the free-agent market. It's not often that even an above-average quarterback becomes available. Cousins capitalized to get a three-year, $84 million guaranteed contract -- a new NFL precedent. And it means he is in line for another payday in 2021 at the relatively young age of 32.

15. Cousins' ripple effect on QB market

The Redskins acquired Alex Smith from the Kansas City Chiefs to replace Cousins. The Chiefs will start Patrick Mahomes, their first-round draft choice in 2017. There also will be new starters in Buffalo (either AJ McCarron or Josh Allen), Cleveland (Tyrod Taylor or Baker Mayfield), Arizona (Sam Bradford, Mike Glennon or Josh Rosen) and Denver (Case Keenum).

16. Colts hired two head coaches

On Feb. 6, the Indianapolis Colts announced Josh McDaniels as their new head coach. On Feb. 11, they announced Frank Reich as their new head coach. In between, McDaniels reneged on his verbal commitment and remained the New England Patriots' offensive coordinator. Other teams with new coaches include the Arizona Cardinals (Steve Wilks), Chicago Bears (Matt Nagy), Detroit Lions (Matt Patricia), New York Giants (Pat Shurmur), Oakland Raiders (Jon Gruden) and Tennessee Titans (Mike Vrabel).

17. Giants listened to offers for Odell Beckham Jr.

Owner John Mara expressed frustration in March about continuing questions concerning Beckham's behavior. Knowing the star receiver's contract would expire after the season, the Giants listened to trade offers, according to ESPN's Adam Schefter. But those offers stopped right around the time that the Los Angeles Rams acquired receiver Brandin Cooks, and Beckham appears set to play in 2018 for the Giants. In what might have been a related move, the Giants decided to stay with veteran quarterback Eli Manning rather than draft one with the No. 2 overall pick. Instead, they used that slot to give Manning (and Beckham) another offensive weapon in running back Saquon Barkley.

18. The Legion of Boom broke up

The Seattle Seahawks' exemplary defensive backfield is no more. Cornerback Richard Sherman signed with the 49ers after his release. Safety Kam Chancellor retired, and the future of safety Earl Thomas remains murky as well.

19. NFL reshaped the league office

Complaints from a number of owners prompted Goodell to shuffle the league's New York-based office. There is now a new chief operating officer (Maryann Turcke) and a new executive vice president of communications and public affairs (Jocelyn Moore). Longtime executives Eric Grubman, Tod Leiweke and Dawn Hudson have all departed or soon will.

20. Gronk bought a horse ... but remained a Patriot

New England tight end Rob Gronkowski, 29, became a part-owner of the horse named after him. More important to Patriots fans, however, Gronkowski was not traded as some around the league believed he would be. He is set to team up for at least one more season with quarterback Tom Brady, who did not buy a horse.

Bonus: Jay Cutler is a (reality television) star

Cutler has emerged as the unexpected star of his wife's television show, "Very Cavallari." The reality TV world totally fell for Cutler's rotation of eye-rolls, dramatic sighs, understated humor and disarming honesty. Seeming to acknowledge the end of his career as an NFL quarterback, Cutler said on camera: "I'm not really looking to do a lot of work right now. I'm looking to do the exact opposite of that."