I've been watching football for virtually my whole life. And I'm still learning about the game.
Here are a few things I'll take away from the 2013 season, as it nears its culmination:
» Sometimes a single play can change a rule in the NFL. The unforgettable image of a severely injured NaVorro Bowman lying near the goal line with the ball clearly in his possession -- on a play that was unreviewable -- was just such a sequence. I think it will be the catalyst to change that aspect of the replay system, at least. And in what arguably has been the worst year for officiating in a while, I wouldn't be surprised to see a major overhaul -- possibly centralizing the review process in New York, and making more plays (perhaps all plays) reviewable.
» Speaking of changes, will enhanced safety precautions increase active-roster sizes? One thing that's clear in the wake of the league's strong adherence to concussion protocol: You're going to have games, like the Chiefs-Colts wild-card showdown, where two or three players exit and are ruled out of a single game because of concussions. Combine that with other non-concussion injuries and you're looking at teams being severely strapped for players by a contest's end. Coaches and general managers will continue to call for larger rosters, while the most cost-conscious owners will counter that rosters are already too big and that the league got along just fine with rosters of 40 men (or fewer) for half a century. Here's a reasonable compromise: Instead of dressing just 46 players, and designating seven members of your 53-man roster inactive, teams should be able to dress all 53 on game day -- but those seven designated players are barred from playing unless injuries force others out of the game. There's no real coherent economic argument against this. You're paying all 53 of those guys anyway. This isn't a matter of finances; it's a matter of safety and common sense.
» The demise of the workhorse back is real. Though many have commented on the running game's postseason resurgence, just two backs (Marshawn Lynch and LeSean McCoy) eclipsed 300 carries this year. Counting pass receptions, McCoy logged a punishing 366 touches in the regular season. It will be interesting to see if the Eagles back can get anywhere near his 5.1 yards-per-carry average in 2014. In general, I think that the 300-carry running back is rapidly becoming a thing of the past.
» Quarterbacks still must make plays from the pocket. Colin Kaepernick's off-balance, midair touchdown throw to Anquan Boldin in the NFC Championship Game was a thing of beauty, although you can be sure any NFL head coach would have chewed him out in film study if it had been intercepted. But you know what? The difference between being a good quarterback and a great quarterback in this league sometimes comes down to being able to throw passes to guys who are covered, and completing them in any way possible. Of course, Kaepernick also made some crucial fourth-quarter mistakes in that game, so he has to reduce the bad decisions. Both Kaepernick and Russell Wilson need Malcolm Gladwell's 10,000 hours -- or in this case, maybe 10,000 throws from the pocket -- to become the quarterbacks they want to be. It's still true in the NFL: You need a passer who can run, not a runner who can pass.
» Big defensive backs are back en vogue. Everyone is looking for rangy, physical corners who can match up with the Demaryius Thomases and Calvin Johnsons of the football world. This, of course, is a driving force behind Seattle's "Legion of Boom" secondary. Interesting side note: The Seahawks' two starting cornerbacks were drafted in the fifth (Richard Sherman) and sixth (Byron Maxwell) rounds, while their star safety (Earl Thomas) was selected in the first. An influx of highly skilled/athletic players at tight end has been one factor in pushing premium safeties -- like Thomas, Kenny Vaccaro and Eric Berry -- up draft boards across the league.
» The postseason format certainly could change, but how? As I mentioned in a previous column, I believe we're quickly moving toward a 14-team playoff field. It just seems like the writing's on the wall. In a related vein, I truly hope the NFL reconsiders its postseason seeding system. Let's seed teams based purely on their records, with a divisional title serving as the first tiebreaker. This just makes the most sense from a competitive standpoint. Though the regular season's value would be somewhat diluted, a record-based seeding system would give teams more to play for down the stretch.
Follow Brian Billick on Twitter @coachbillick.