The AFC South knows all too well that a quarterback can make or break a season.

Quarterback play, unsurprisingly, has been a significant factor in the division’s fluctuating balance of power over the years. But given the high level of variance in the careers of AFC South quarterbacks, there are multiple realistic outcomes for the 2018 regular season.

Here are my over/under win-total picks for the AFC South.

Jacksonville Jaguars

Pick: Over 9 wins -110 (Intertops)

Some might say the Jaguars exceeded expectations last season, and they wouldn’t necessarily be wrong – Jacksonville enjoyed one of the biggest turnarounds from 2016, going from a 3-13 record to a 10-6 campaign and a trip to the AFC Championship Game.

But it’s also fair to say the Jaguars underachieved in 2017.

Based on Pythagorean wins, the Jaguars should have actually won close to 12 games. Even if Jacksonville “regresses” in 2018 by, let’s say, two wins, Pythagorean projections suggest that would still be enough to get them over the win total.

A run-first offense and an elite defense fused to turn Jacksonville into a contender that should have made a trip to the Super Bowl but collapsed against the Patriots. Blake Bortles didn’t have to be a hero last season on the way to his lowest interception total since entering the league.

Now Jacksonville gets one of the easiest schedules in the league (25th) and brings back the key pieces that helped the team morph into an AFC juggernaut. I think the Jags are here to stay and will make an even bigger leap in ’18. This is one of my favorite win totals for the season.

Tennessee Titans

Pick: Over 8 wins -110 (BetOnline)

The Titans’ offense didn’t deliver on its untapped potential in 2017.

Not only was health and average production in the skill corps a problem, the straw that stirs the drink endured his own fair share of struggles. Marcus Mariota, expected to take another step forward in Year 3, went the complete opposite direction.

There are a handful of reasons to believe Tennessee can significantly improve its No. 19 scoring offense from a season ago:

  • New offensive coordinator Matt LaFleur turned the Los Angeles Rams around last year and was in the thick of things in Atlanta in 2016 when Matt Ryan posted career highs in yards (4,944) and touchdowns (38). He’s innovative and he’s got the right pieces to work with in Tennessee.
  • Pro Football Focus’ QB Annual piece on Marcus Mariota dug into his 2017 season and determined the dual threat was a victim of misfortune, with only 15 turnover-worthy throws all season. Coincidentally, Mariota threw 15 interceptions, compared to just 13 touchdowns.
  • With a healthy Corey Davis, a big-play threat in Taywan Taylor, the reliable Delanie Walker, the underrated Rishard Matthews, and another depth tight end in Jonnu Smith, this unit is more complete and will be just fine under LaFleur.

The club also made additions on both sides of the ball, with running Dion Lewis and cornerback Malcolm Butler from New England among the notable new faces.

Only the Texans play an easier schedule, and I think Tennessee is in for a huge season under first-year head coach Mike Vrabel.

Houston Texans

Pick: Under 8.5 wins +120 (BetOnline)

It takes a lot of trust in the Texans to invest in the glimmer of hope they offered with Deshaun Watson healthy.

Watson injected life into the offense immediately. The transition to the NFL looked seamless as the former national champ threw six more touchdowns than Mariota despite playing in eight fewer games. He won shootouts, showing he could take the game over as a rookie. Then, he was lost for the season.

Watson isn’t the only one returning from injury in 2018. J.J. Watt hasn’t been healthy the last two seasons. Will Fuller only played in 10 games following a serious collarbone injury. Whitney Mercilus was done for the season in Week 5.

If the team can keep its stars off the injury report, the Texans still have a glaring weakness: the offensive line. PFF went so far as to call last year’s unit “one of the worst offensive lines we’ve seen in the PFF era” and left little hope that it could rise from the bottom of the league rankings.

Houston has the feel of a 10-win team if everything goes well and a five-win club if it doesn’t. Given my projections for Tennessee and Jacksonville, I’ll call for the latter.

Indianapolis Colts

Pick: Under 7 wins +131 (Bookmaker)

Let’s say nice things about the Colts’ offense:

Andrew Luck is finally back in the fray. In terms of a player’s value to his team, Luck is somewhere at the top of the list. You couldn’t pay me to watch a Luck-less Colts game, but his connection with T.Y. Hilton will be one of the most productive in the league if the quarterback stays healthy. And for once, there’s reason to believe the Colts will at least be serviceable on the line.

Now let’s say nice things about the Colts’ defense:

Malik Hooker.

Luck will likely do his best Aaron Rodgers impression and get the most out of the more unknown players in his supporting cast. But the downside in backing this team to go .500 is obvious: There’s legitimately no defense to rely on, putting pressure on a quarterback who hasn’t played a live snap in two years.

I have the Colts getting swept by the NFC East and nabbing a win apiece from Houston and Tennessee. Indianapolis falls into my fun-but-not-good category of teams right alongside Miami, Chicago, and both New York squads.

Alex Kolodziej is theScore’s betting writer. He’s a graduate of Eastern Illinois who has been involved in the sports betting industry for 11 years. He can quote every line from “Rounders” and appreciates franchises that regularly wear alternate jerseys. Find him on Twitter @AlexKoIodziej.

(Photos courtesy: Getty Images)