The SEC is in a constant state of change.

That seems to have accelerated in the last five years, as even Vanderbilt has enjoyed a run in the Top 25.

A myriad of factors influence the direction of all 14 programs on a yearly basis, including coaching decisions, facilities upgrades, recruiting and injuries.

Judging the time period between now and the summer of 2018, here are three SEC teams we feel like will trend in a positive direction and three who could face regression.

MOVING UP

TEXAS A&M

Primary Reason: Solving the defense

Johnny Manziel proved a tremendous asset to the Aggies on the field, but if you can believe it, even more so off it. His polarizing image and the team’s thrilling offense helped launch a cascade of new financial contributions, which in turn funded the remaking of Kyle Field.

But that offense, which averaged 44.5 and 44.2 points per game in ’12 and ’13, may have masked the urgency of repairing a fast-eroding defense. A&M lost four games in Manziel’s final season despite one of the country’s most explosive offenses.

The defense went from a major liability late in the ’13 season to an impassable obstacle last year as the team transitioned to Kenny Hill and then Kyle Allen last season, needing to replace superstar receiver Mike Evans a high first-round NFL draft choice at left tackle for a second consecutive year.

But coach Kevin Sumlin managed to wrench John “The Chief” Chavis from LSU in the offseason, and also made a subtle but important decision to hire Dave Christensen as offensive line coach.

Young players like Armani Watts, Myles Garrett and Daylon Mack likely will become SEC stars in ’15 and ’16. It’ll also help that Chavis’ one-gap, attack-oriented scheme features the kind of simplicity and aggression that pairs well with a high-octane offense. But the team still lacks depth and talent at several positions, namely cornerback and linebacker.

By 2017, and maybe sooner, the Aggies’ defense should be full systems go. Meanwhile, young offensive talent like Allen, Kyler Murray, Speedy Noil, Christian Kirk and likely Greg Little will mature into upperclassmen who will try to approximate the Manziel-level offensive output in College Station.

It never will be easy for Texas A&M in the SEC West. Baylor and TCU are national powers at the moment, and Texas should finally revive. But as long as the Aggies keep recruiting and developing, the team should see a title window start to open up.

FLORIDA

Primary Reason: Reviving the passing game

New coach Jim McElwain already has faced a few mini-public relations battles.

First, he had to lower expectations after the man he replaced, Will Muschamp, made comments about how much talent he left behind in Gainesville. (Muschamp and McElwain did some minor sniping at each other through the media as well.)

Now, he’s getting criticism — including on this website — for his interesting recruiting practices. Despite landing players like CeCe Jefferson and Martez Ivey on short notice after his hiring, the ’16 class is saturated with three-star talents. That must improve by February, much less the next recruiting cycle, or the Gators rebuild will get prolonged even further.

McElwain also must groom a pair of quarterbacks in Treon Harris and Will Grier that got recruited during the Muschamp era (not to mention a stable of receivers with a wide range of talents, a mark of the many offensive coordinators that have blown through town recently).

But the word is out: Florida’s offensive identity is about to return. McElwain’s track record speaks for itself, and I won’t detail it all here. I do expect the Gators to a) begin to throw the ball effectively once again, and b) as a result, start to attract some of the marquee skill-position prep talent from the state that previously avoided the conservative, run-heavy Muschamp offense.

There are lots of areas to fix on both sides of the ball — the linebacker corps is thin and beat up — but the defense should continue to perform as a Top 25 unit nationally. It’ll take two or three years, but once McElwain figures out recruiting at a major institution and gets the offense humming, Florida will be a national force once again.

TENNESSEE

Primary Reason: A major cultural shift

Lane Kiffin felt more like a mercenary, and Derek Dooley was a recruiting disaster the likes of which a major SEC program may never have seen.

Tennessee’s streak of placing a player in the NFL draft ended this year at 51 years. In January, the team won its first bowl game in seven seasons.

More importantly, touted recruits are flocking to Knoxville in droves — many of them as early enrollees who are serving as de facto additional recruiters. The team’s marketing, especially on social media, never has been stronger. Coach Butch Jones has rallied the alumni and fan base. Tennessee has become a cool football program for everyone involved.

The leap from historically bad to a mediocre bowl game took time, but the gap between decent to national contention may be even bigger. On the plus side, Jones and the Vols have a few years’ head start on McElwain, the resources afforded to only the teams with elite traditions and a healthy swell of talent and experience among the underclassmen.

It won’t be a surprise if Tennessee finishes the 2015 season ranked in the Associated Press Top 25, and the prospects for the ’16 and ’17 seasons should be even better.

MOVING DOWN

SOUTH CAROLINA

Primary Reason: Uncertainty at head coach

The Gamecocks’ three consecutive 11-win seasons, all Top 10 finishes, mark another impressive entry on Steve Spurrier’s long coaching resume, even though the team didn’t manage to win a conference title.

No one knows exactly when Spurrier will retire, but there’s a strong likelihood that the team’s 2016 class won’t play for the Head Ball Coach for their entire college careers. That’s causing the team’s recruiting efforts to derail, starting when Spurrier mentioned retirement publicly near the end of the ’15 recruiting cycle.

The prep talent in South Carolina also has dipped in the last couple years, as there hasn’t been another Jadeveon Clowney type talent for the Gamecocks to remain in-state. The defense, thanks to a weak pass rush and a green secondary, imploded last year. The team no longer has a bulletproof roster or an NFL-caliber quarterback.

As programs like Florida and Tennessee ascend back to their normal place at the top of the SEC East, it’ll get even more difficult for South Carolina to prevent a slide down the standings.

MISSOURI

Primary Reason: Regression to the mean

The Tigers have won division titles at a much higher frequency with coach Gary Pinkel — five in the last eight seasons. Not to say that Mizzou won’t ever win the SEC East again, but historically, that’s far beyond the program’s usual success rate.

There are signs that Pinkel and the Tigers have elevated themselves permanently. The move to the SEC, and the subsequent flood of cash, helps. In a few years, the football team should elevate its facilities. Combined with so much winning and a progressing regional brand, the team is in position to leverage even better recruits.

Pinkel and his staff have done a commendable job of developing players. This team plays like an SEC club along the line of scrimmage, running the ball with power and getting after teams up front on defense.

But Mizzou has enjoyed a considerable amount of luck the last two seasons as well. It helps that some of the traditional SEC East powers have floundered. The team hasn’t suffered too many major injuries or dismissals, and when it has, there have been others to fill those roles (Bud Sasser with Dorial Green-Beckham and Maty Mauk with James Franklin).

What happens this fall, with a huge talent drain at receiver and defensive line? What happens next year, when a number of experienced, successful offensive linemen depart? Can Pinkel and the staff keep this team at the top of the SEC East every year, or will it fade ever so slightly?

The latter seems likely. This is not to say that the Tigers will put out an inferior football team. But even if Mizzou remains a Top 25 program, more or less, the results may not be as spectacular.

LSU

Primary Reason: Overwhelming competition

The 2014 season was a microcosm of the Les Miles era in Baton Rouge.

The team featured a tremendous defense that got stouter in the later stages of the season. The offensive line cleared a path for an impressive running game. LSU rolled out a deep pool of talent at receiver and in the secondary. But the team could’t get it together at quarterback.

Either due to a lack of talent — or, more commonly, character issues that either limit the players’ development or force them into trouble — LSU has failed to get the job done at quarterback more times than not.

Now the team must account for the loss of John Chavis. An elite talent pool remains, but unless a magical solution appears at quarterback, even a quarter-notch decline of that unit will make a significant impact.

More worrisome for LSU: the rest of the division is getting scary good. Nick Saban and now Miles have set a standard. The Tigers are expected to win 10 games a year and claim SEC West titles every few seasons.

But Alabama appears lodged near the top as a constant nemesis for years to come. Texas A&M (Kevin Sumlin and Chavis) and Auburn (Gus Malzahn and Will Muschamp) have paired renowned offensive and defensive coaches. Hugh Freeze has leveraged excellent recruiting and turned Ole Miss into what should be a perennial Top 25 team. Arkansas believes it has something going with Bret Bielema, and even Mississippi State was able to beat LSU in Death Valley last season.

Until this point, the SEC West has been a three-team battle every year between LSU and the Alabama schools. But, in part due to the ridiculous revenue streams circulating to every conference member, there no longer are any weak links in the division. That makes it harder for every program, but LSU seems the most logical choice for a team that may get downgraded. Don’t be surprised if 8-4 or 9-3 seasons become the new norm in Baton Rouge.