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Last Season: 5-11

Third in AFC South

Preseason power ranking: 19

ESPN Illustration

The Jaguars' defense has been among the league's worst the past three seasons, recording the fewest interceptions in the NFL (26) and ranking 31st in scoring defense (27.3 points per game), 31st in third-down defense (43.8 percent) and 29th in total defense (375.0 yards per game) in that span. They made significant upgrades by adding DT Malik Jackson, FS Tashaun Gipson, CB Jalen Ramsey and CB Prince Amukamara. In addition, DE Dante Fowler Jr. is back after missing his rookie season because of a torn ACL. The Jags shouldn't offer an easy day for opposing quarterbacks any longer, especially division foes Andrew Luck and Marcus Mariota. If the defense can go from giving up 28.0 points per game in 2015 to around 21.0, that will be a big enough improvement to make the Jaguars contenders for the AFC South title.

The offense's success will come down to whether the offensive line is any better in 2016, and that much is still uncertain. Will it be Kelvin Beachum, who is coming off a torn ACL, or Luke Joeckel at left tackle? Will the loser of that battle be able to play left guard? Three players -- C Brandon Linder, RG A.J. Cann, and RT Jermey Parnell -- are going into their second seasons as full-time starters. QB Blake Bortles has been sacked 106 times in 2014-15 -- the most in NFL history in a quarterback’s first two seasons -- and he can't continue to take that kind of beating, especially not in a division with J.J. Watt. If the offensive line isn't any better, the offense will still struggle on third down (35.1 percent last season) and in the red zone (53.7 percent last season), and that makes it tough to sustain drives and win games, even in a division that's as muddled as the AFC South.

Jaguars' percentage chance to win each game

Sept. 11 vs. Green Bay: 43.9

Sept. 18 @ San Diego: 38.6

Sept. 25 vs. Baltimore: 52.3

Oct. 2 vs. Indianapolis: 40.0

Oct. 16 @ Chicago: 47.4

Oct. 23 vs. Oakland: 53.9

Oct. 27 @ Tennessee: 48.5

2Nov. 6 @ Kansas City: 28.1

Nov. 13 vs. Houston: 48.4

Nov. 20 @ Detroit: 59.6

Nov. 27 @ Buffalo: 34.6

Dec. 4 vs. Denver: 48.1

Dec. 11 vs. Minnesota: 54.2

Dec. 18 @ Houston: 33.9

Dec. 24 vs. Tennessee: 66.7

Jan. 1 @ Indianapolis: 32.7

Michael DiRocco’s game-by-game predictions

Fun fact: Blake Bortles’ backup is still 31-year-old Chad Henne! (We know, right?) Bortles has weapons all around him but has to bring down the interceptions (35 in two years). -- Dan Graziano

The Jaguars failed to sign Olivier Vernon in free agency and are instead going with Fowler and rookie Yannick Ngakoue as their primary edge rushers. Fowler, the No. 3 pick in 2015, was great early in training camp but struggled against the New York Jets and Tampa Bay Buccaneers, and defensive coordinator Todd Wash challenged him to watch more film on his own and transfer what he's learning in meetings to the field. Jaguars coaches seem to believe he's learned he can't just rely on his athletic ability and will be good enough to approach double-digit sacks. The defense has sorely lacked playmakers over the past three seasons, and Fowler can be one.

Marqise Lee hasn't produced much during his first two seasons (52 catches for 613 yards and 2 TDs) but that's because he has battled hamstring injuries, missing nine games. However, he was healthy in the spring and was the Jaguars' most impressive offensive player. He had a slight hamstring strain on the first day of camp, and in the past that would have set him back a month, but he was back on the field in 12 days. Lee's speed is an element the Jaguars' offense is missing, and if he stays healthy he could easily top his totals from his first two seasons.

Owner Shad Khan said a winning record in 2016 is "everybody's reasonable expectation at this point." For that to happen, the defense has to be better. The thing is, it doesn't have to be a top-10 defense. It just needs to go from being one of the league's worst to middle of the pack, especially on third down, in the red zone and in scoring (28.0 PPG last year). The offense has plenty of playmakers (WRs Allen Robinson and Allen Hurns and TE Julius Thomas for starters) and will score points, even if the line is still below average. But they can't continue to play from behind. Topping six victories will be tough if the defense can't make more plays and keep games close.