Today, our four-part NFL preview continues with a look at eight teams that should improve in 2015. As I warn every year, the expectation these teams will get better doesn’t necessarily mean they’ll be better than the teams I predicted will decline, even if I do end up being right about both sides. Many of those teams that should fall back toward .500 were playoff-caliber units last season, and many of these that should rise to the 8-8 mark were disappointments.

More information on the slightly unfamiliar numbers included in this piece can be found in this statistical primer. You can also check out the eight teams I expect to compete for the first overall pick in this year’s draft here. And if this isn’t enough preview for you, you can listen to the preview podcasts I recorded for each division with Robert Mays here. If that’s not enough for you, seek professional help.

Atlanta Falcons

Key 2014 Results
Record: 6-10 (NFL rank: 23)
Pythagorean Wins: 7.1 (NFL rank: 22)
Pythagorean Difference: minus-1.1 (NFL rank: 28)
Record in Close Games:¹ 2-4 (NFL rank: 23)
Strength of Schedule: 0.475 (NFL rank: 27)
Turnover Margin: plus-5 (NFL rank: 11)

Poor Matt Ryan sold his soul to light beer, and his reckoning has come over the past couple of seasons. After the 2012 season, you would have sworn Ryan was one of those special quarterbacks immune to the idea that teams can’t continually win a disproportionately high percentage of their close games, given that he had started his career 27-10 in games decided by a touchdown or less. Since then, he and his Falcons have gone 5-11 in those same games. That includes the legendarily ugly loss that Atlanta suffered in London against Detroit and a game in which Brian Hoyer, of all people, marched down the field on a game-winning two-minute drill.

Although Atlanta fans surely didn’t feel this way at the time, the 34-3 season-ending home blowout at the hands of the Panthers, which cost the Falcons the NFC South, was probably a blessing in disguise. Atlanta might very well have been able to beat a Ryan Lindley–led Cardinals team at home, but it didn’t have much of a prayer of getting past the Seahawks in Seattle. The difference in draft position alone amounted to 17 spots, an enormous swing over the course of seven rounds’ worth of draft picks. Without considering trades, the difference in draft capital between the Falcons and Panthers per Chase Stuart’s chart was equivalent to the 31st overall pick.

Most importantly, it eliminated any flimsy pretense for the Falcons to retain head coach Mike Smith, who hadn’t worn out his welcome as much as he had ripped it to shreds and burned the ashes. Firing an unloved head coach isn’t always a cure-all for a team’s problems, but there’s certainly logic behind the idea of moving on from Smith to Seattle defensive coordinator Dan Quinn, who took over and placed former Browns offensive coordinator Kyle Shanahan in charge of the offense.

Atlanta’s biggest problem over the last two seasons has been nurturing any semblance of a pass rush. Between 2013 and 2014, the Falcons’ sack rate of 5.0 percent has been 23.3 percent below the league-average rate of 6.5 percent. That’s the largest difference in the league. The good news is that the last team to be so far gone was the 2012-13 Jaguars, who were 26.8 percent below league average. Jacksonville also hired a member of Seattle’s staff to rebuild the defense in Gus Bradley, and while it took a year, he eventually got the pass rush going; the Jags took down opposing passers on 7.6 percent of their dropbacks last year, the fifth-highest rate in the league.

Qualitatively, the Falcons should get more out of their rush this year, having spent their first-rounder on Clemson’s Vic Beasley and imported situational rusher O’Brien Schofield alongside Quinn from Seattle. There’s enough talent on the Atlanta starting 11 to imagine Quinn producing an upper-echelon defense, but injuries and the usual lack of depth will probably prevent the Falcons from hitting those heights reliably; indeed, free-agent pickup Brooks Reed is already out until October after undergoing groin surgery.

On offense, Atlanta can’t be much more injured than it has been over the last two seasons; it was 27th in Offensive Adjusted Games Lost in 2013 and 30th last season. Getting rid of tackle Sam Baker, who played nine games over the last two seasons, was probably a step in the right direction. Thirty-three-year-old receiver Roddy White has already undergone elbow surgery and is expecting to have his knee drained at least once during the season, but he should (somehow) be ready for Week 1.

The late addition of Titans guard Andy Levitre, acquired via trade over the weekend, was interesting. Levitre bombed as a big-ticket free agent in Tennessee, but Atlanta’s emphasis on zone blocking under Shanahan should allow him to return to the scheme under which he excelled in Buffalo. It’s unclear how much of Levitre’s salary the Falcons picked up as part of the deal, but it’s worth the risk; even if Levitre just ends up as solid offensive line depth, that would be a massive upgrade for an oft-struggling Falcons front five.

Best-Case Scenario: Julio Jones wins offensive player of the year as he stays healthy and produces a career year at age 26; Beasley wins defensive rookie of the year in a double-digit sack campaign; and Desmond Trufant rightly receives his due recognition as one of football’s top cornerbacks. Atlanta goes 11-5 and wins the South.

Worst-Case Scenario: Teams march up and down the field on what was the league’s worst defense in 2014, Jones suffers another foot injury two months into his five-year extension, and the Falcons trade wins and losses in a season’s worth of shootouts, finishing 5-11.

Chicago Bears

Joe Robbins/Getty Images

Key 2014 Results
Record: 5-11 (NFL rank: 26)
Pythagorean Wins: 5.1 (NFL rank: 26)
Pythagorean Difference: minus-0.1 (NFL rank: 16)
Record in Close Games: 0-4 (NFL rank: 31)
Strength of Schedule: 0.506 (NFL rank: 13)
Turnover Margin: minus-5 (NFL rank: 22)

That record in close games would usually be part of the reason why I would suspect that the Bears will improve in 2015, but it’s also a little misleading, since the Bears won four games by exactly eight points each. I’ve traditionally kept the margin for games decided by one score or less to seven points as opposed to eight for two reasons: It allows for comparisons to teams that played before the two-point-conversion era, and the two-pointer is hardly a guarantee. In most cases, the distinction doesn’t make a huge difference; this is obviously an exception.

Even without using that evidence, I’m pretty confident the Bears should be improved in 2015, primarily because of their decision to hire John Fox and Vic Fangio to rebuild a defense that ranked 25th and 28th in DVOA in the past two seasons. As I wrote after Fox was fired by the Broncos, his track record in improving defenses is impeccable. He’s had four jobs as a defensive coordinator or head coach in the NFL. He’s produced above-average defenses in terms of DVOA in 18 of those 20 seasons, and he’s turned each of his defenses into a top-10 unit within two years:

The Broncos stand out as the obvious blueprint, as they were also a team with an aging secondary and a couple of stars in the front seven before Fox took over. It helped that Fox drafted Von Miller, of course, but unknowns like Danny Trevathan, Brandon Marshall, and Chris Harris all became key contributors to Fox’s defense. And while he got to share the workload with an above-average defensive coordinator in Jack Del Rio, Fox is teaming up here with Fangio, one of the best defensive coordinators in football during his time with the 49ers.

I have major concerns with the secondary, but it’s not hard to imagine the Bears manufacturing one of the league’s best pass rushes. As much as Jared Allen looked out of sorts at times last year, his 5.5 sacks undersell his effectiveness as a pass-rusher, given that he had 18 quarterback knockdowns. The same is true for free-agent signing Pernell McPhee, who was quietly one of the league’s most effective pass-rushers last year. He finished with 7.5 sacks and a whopping 26 quarterback knockdowns, tying him with Ziggy Ansah for the fourth-highest total in football even though McPhee was playing just over 32 snaps per game. He knocked down opposing quarterbacks once every 19.8 snaps, which was the best rate in football.² He could be an absolute terror if Fangio and Fox unleash him in 2015.

And yes, it’s even realistic to expect Jay Cutler to be better in 2015. It’s always easy to take shots at Cutler, and he was bad last year, but much of that owed to a career-high 12 fumbles, which isn’t likely to recur. The Bears turned the ball over far more frequently last year than they have since the beginning of the Cutler era, in terms of turnover rate on a per-possession basis:

Chances are they’ll fall somewhere in the middle of those numbers in 2015. It would help if seventh overall pick Kevin White were available, but a stress fracture in his shin should keep the West Virginia product out until midseason. The Bears probably aren’t ready to make the leap back into the postseason, but with a less destructive offense and a more productive pass rush, they should return to respectability in 2015.

Best-Case Scenario: New offensive coordinator Adam Gase forms an emotional bond with his quarterback, inspiring Cutler to his best season as a pro. Fangio and Fox mold a top-12 defense out of the front seven, and the Bears sneak into the playoffs as a 10-6 wild card.

Worst-Case Scenario: Cutler’s toast, and so are the Bears.

Miami Dolphins

Mike Ehrmann/Getty Images

Key 2014 Results
Record: 8-8 (NFL rank: 17)
Pythagorean Wins: 8.4 (NFL rank: 15)
Pythagorean Difference: minus-0.4 (NFL rank: 18)
Record in Close Games: 2-3 (NFL rank: 21)
Strength of Schedule: 0.514 (NFL rank: 8)
Turnover Margin: plus-2 (NFL rank: 14)

I wrote at length about the Dolphins during Brink Week. My concerns about their depth still stand, especially given that I wrote that column before Louis Delmas tore his ACL. Starting corner Jamar Taylor missed the last two weeks of the preseason with a quad injury and returned to practice only this past week, and nominal backup Will Davis barely made the roster after an ugly preseason. The team’s long-standing flirtations with Evan Mathis also failed to come to fruition after Mathis signed with the Broncos.

The good news is that the team’s first-round pick, wideout DeVante Parker, was able to suit up for Miami’s final preseason game after recovering from foot surgery and should be available in Week 1, albeit on a limited snap count. Left tackle Branden Albert, who tore his ACL last November, should also be on the field. Every team needs to stay healthy, but the Dolphins are one of the thinnest, most top-heavy teams in football. They need all hands on deck for as many weeks as possible to make the postseason.

Best-Case Scenario: Ndamukong Suh revitalizes the Miami defense, as he combines with Cameron Wake to form the best one-two pass-rush combination in football. Lamar Miller breaks out with a career year as the Dolphins go 11-5.

Worst-Case Scenario: Suh underwhelms, Brent Grimes suddenly gets old, and the Dolphins run out one of the worst secondaries in football. The Ryan Tannehill who nearly got benched last year shows up as the Dolphins fall into the AFC East cellar.

Minnesota Vikings

Ronald C. Modra/Sports Imagery/Getty Images

Key 2014 Results
Record: 7-9 (NFL rank: 20)
Pythagorean Wins: 7.5 (NFL rank: T-18)
Pythagorean Difference: minus-0.5 (NFL rank: T-19)
Record in Close Games: 4-4 (NFL rank: 13)
Strength of Schedule: 0.474 (NFL rank: 28)
Turnover Margin: minus-1 (NFL rank: 18)

If you listen to the Grantland NFL Podcast, you know that Mays and I have a rare mutual affinity for the Vikings. Given how well that’s worked out for the Buccaneers in the past, I wouldn’t blame you for suggesting the Vikings are doomed, but there is a lot to like here. The Vikings are a young, deep, talented team, with a promising second-year quarterback and a well-regarded head coach. They upgraded their weakest spots on the roster this offseason and will bring back a former league MVP who sat out virtually the entire 2014 season without any injury. There are a lot of reasons to be hopeful in Minnesota.

That starts with the idea that the Vikings managed to come away with the best quarterback from the 2014 class with the final pick of the first round. It’s fair to say offensive coordinator Norv Turner installed a very conservative scheme for Teddy Bridgewater, likely owing both to Bridgewater’s strengths, the receivers he had to work with, and concerns about flailing left tackle Matt Kalil. Bridgewater showed flashes of excellent play early, notably in his debut start against the Falcons, before taking strides as the season went along.

Split his 12 starts into two six-game stretches, and you see a more confident, successful quarterback emerging:

Bridgewater improved from 19th in QBR to 12th over those final six games, placing him above the likes of Matthew Stafford, Philip Rivers, and Blake Bortles, who was down in 32nd place with a QBR of 20.1. (I’ll spare you the Johnny Manziel numbers.) There’s still plenty of time for all of this to play out, and it would shock nobody if Bortles took a step forward in 2015, but Bridgewater might take another step forward, too. He was a league-average quarterback as a rookie last year, and his cap hit this season is $1.5 million. That’s one of the most valuable assets in football, even if Bridgewater stays at this level for the next three seasons.

Having a competent quarterback making peanuts makes it easier to swallow an enormous cap hit for a star running back, which is one of the reasons why the Vikings were comfortable guaranteeing most of Adrian Peterson’s 2016 salary. It would be unfair to expect Peterson to show up and deliver the run-over-everyone MVP campaign from 2013 again, but it’s hard to imagine a bigger talent upgrade than replacing Matt Asiata with arguably the league’s best running back.

The Vikings also upgraded the weakest points of their 23rd-ranked defense from a year ago in the draft. With Xavier Rhodes establishing himself as an above-average cornerback last season, the Vikings desperately needed to find a starter across from their former first-rounder. Enter 11th overall pick Trae Waynes, who will be given time to develop behind veteran Terence Newman, who himself is familiar with Mike Zimmer’s scheme from their time in Cincinnati. The additions will also push Captain Munnerlyn into the slot, where he’s been effective in the past. Second-rounder Eric Kendricks also gives the Vikings the rangy middle linebacker they’ve lacked over the last several seasons.

You can see Zimmer building a defense to emulate the one he had during his time with the Bengals, who placed (and still place) a high priority on cornerback depth and athletes throughout the front seven, trusting that the coaching staff can develop those weapons into solid NFL contributors. It remains to be seen whether Zimmer and his crew will be able to pull that off, but the early returns on 2014 first-rounder Anthony Barr are good. This was the league’s fourth-youngest defense last season, and it might play even younger in 2015.

And yet, for all their promise, there are reasons to be skeptical about the Vikings taking that enormous leap in one fell swoop this season. The offense around Bridgewater was still very conservative last season, and while the Vikings added another weapon in Mike Wallace, it’s hard to see Wallace excelling as a deep threat with Bridgewater’s admittedly fringy arm strength under center. There’s promise elsewhere in the receiving corps with Charles Johnson, Jarius Wright, and whatever the Vikings can squeeze out of Cordarrelle Patterson, but it would be difficult to say with any sort of certainty that one of those guys will step up and justify 120 targets in 2015. It’s also tough to count on talented tight end Kyle Rudolph, who missed 15 games over the last two season with various injuries.

The offensive line is also an area of serious concern. Right tackle Phil Loadholt is already done for the year after tearing an Achilles; he’ll be replaced by rookie T.J. Clemmings, who fell to the fourth round over long-term concerns about his foot. Right guard Mike Harris is really a utility lineman being stretched into a starting role, but most disconcertingly, the aforementioned Kalil was bad in 2013 and one of the worst left tackles in football last season. He had both of his knees scoped in January, and while Kalil still holds promise after making the Pro Bowl as a rookie in 2012, he’s the biggest question mark facing this team in 2015. In all, it seems to add up to an improved Vikings team, if not necessarily a trip to the playoffs.

Best-Case Scenario: The offense moves into the top 10 with the return of Peterson, Bridgewater stays healthy and runs one of the most efficient passing games in the league, and Zimmer coaches the league’s best young defense to an 11-5 mark and the fifth seed in the NFC.

Worst-Case Scenario: Bridgewater gets hurt, the offensive line collapses, Peterson runs like a guy with 2,000-plus carries on his legs, and the secondary never comes together as Minnesota finishes 5-11.

New Orleans Saints

Alex Menendez/Getty Images

Key 2014 Results
Record: 7-9 (NFL rank: 20)
Pythagorean Wins: 7.5 (NFL rank: T-18)
Pythagorean Difference: minus-0.5 (NFL rank: T-19)
Record in Close Games: 3-5 (NFL rank: 22)
Strength of Schedule: 0.473 (NFL rank: 29)
Turnover Margin: minus-13 (NFL rank: 31)

That last figure seems like the most interesting one to me if I’m looking at how the Saints performed in 2014 and what’s likely to change for them in 2015. Here’s what this team’s turnover differential has looked like during the Brees era:

It seems weird the Saints haven’t had a better average performance in terms of turnover margin during Brees’s run, but their average mark has been minus-2.7; that would be a reasonable projection for what they’ll post in 2015, and it would be a dramatic improvement on what they did a year ago. One old, reasonably simplistic measure suggests each turnover is worth four points.

A 10-turnover improvement from the Saints would then be worth 40 points. Split that evenly — give 20 points to the offense and take 20 away from the defense — and make no other changes, and their Pythagorean expectation goes from 7.5 wins to 8.4 wins; in other words, merely regressing toward their historical average in turnover differential could be worth close to a full win by itself.

It’s even reasonable to wonder whether the Saints are more likely to post a positive turnover differential this season because of how they may end up shifting their offense. Running plays are obviously far less likely to produce turnovers than passing plays; 0.7 percent of running plays in 2014 resulted in a giveaway, while across the wide range of strip-sacks, interceptions, and fumbles after receptions, 3.2 percent of passing plays produced giveaways.

The offseason moves made by the Saints seem to suggest they are moving to more of a run-first approach. They got rid of Jimmy Graham and Kenny Stills without acquiring a notable replacement for either. They picked up Pro Bowl center Max Unger in the Graham trade, spent their first selection in the draft on Stanford tackle Andrus Peat, and used most of the cap space they had left to lock up a pair of running backs, incumbent Mark Ingram and receiving back C.J. Spiller.

I would be scared to make too many changes, if only because the Saints really weren’t very bad at all on offense last season. New Orleans finished seventh in offensive DVOA, and the drive statistics suggest their real problem was almost exclusively turnovers — 76.6 percent of Saints series produced a first down or a touchdown, the highest rate in football. New Orleans was second in yards per drive and fifth in points per possession, with the latter figure artificially deflated by the fact that the dismal Saints defense handed them the league’s fifth-worst average starting field position. If the turnovers regress toward the mean and the field position improves itself, the Saints might not need to make any serious changes.

The defense, on the other hand, underwent some much-needed pruning this offseason. I’m just not sure if all the changes add up to a better unit. The Saints should be better at cornerback, having added Brandon Browner to replace the subpar starting combination of Patrick Robinson and Corey White. And CFL refugee Delvin Breaux has a lot of promise as a nickel cornerback. They spent first- and second-round picks on much-needed help at linebacker, where Stephone Anthony and particularly edge rusher Hau’oli Kikaha should both play meaningful roles, and took a flier on former big-money free agent Dannell Ellerbe.

At the same time, none of those players is remotely a sure thing. And some of the few players who would seem to be likely contributors on this defense are absent. As abhorrent as Junior Galette’s behavior off the field might have been, his release over the summer came too late for the Saints to find a meaningful replacement for the player who had been their best pass-rusher. Safety Jairus Byrd, who was expected to return from a torn meniscus that ended his 2014 season after four games, is yet to practice and will likely miss the beginning of the season. And no. 1 cornerback Keenan Lewis is out until October after undergoing hip surgery.

That list doesn’t include the other depth pieces who might have contributed. Starting nose tackle Brodrick Bunkley couldn’t pass his physical and was waived. Third-round cornerback P.J. Williams tore his hamstring and was placed on injured reserve. And despite the injuries and poor play at cornerback over the past two seasons, 2014 second-rounder Stanley Jean-Baptiste failed to make the team, becoming the first second-rounder from last year’s draft to be released. The Saints got just eight defensive snaps from Jean-Baptiste.

If he wasn’t going to play, it made sense to move on from the second-rounder, but it raises questions about what the Saints are doing. If they evaluated Jean-Baptiste as being worth a second-rounder and couldn’t even get enough out of him to justify keeping him on the roster for more than a year, what’s to say they’re going to get the most out of the guys they have left?

Best-Case Scenario: The offense clicks, the turnovers disappear, and the secondary coalesces once everybody gets healthy. The Saints take advantage of the mediocrity of the NFC South and win the division at 11-5.

Worst-Case Scenario: The defensive changes fail to take, Rob Ryan gets fired midseason, Mickey Loomis follows at the end of the year, and the Saints trade Brees to get out of cap hell.

New York Giants

Jim Rogash/Getty Images

Key 2014 Results
Record: 6-10 (NFL rank: 23)
Pythagorean Wins: 7.5 (NFL rank: 18)
Pythagorean Difference: minus-1.5 (NFL rank: 31)
Record in Close Games: 0-3 (NFL rank: 31)
Strength of Schedule: 0.495 (NFL rank: 19)
Turnover Margin: minus-2 (NFL rank: 19)

There’s less article left than you think … the Giants were profiled in our Brink Week series. Since then, Tom Coughlin has scoffed at the idea that a computer might be able to tell him when players need to rest. In other news, Coughlin hasn’t read the Brink Week article about how he’s had the most injured team in football over the past two seasons.

I’m very skeptical the Giants will be good. I find it very hard to imagine they’ll make the playoffs without long-term injuries keeping both Tony Romo and Sam Bradford out of their respective lineups. But it’s fair to say they were unlucky last year, and teams with that sort of gap between their Pythagorean expectation and win total almost always improve the following year. If the Giants could somehow just get healthy, they could actually compete for a postseason berth. To be fair, a computer told me that.

Best-Case Scenario: Coughlin finds a way to turn injuries off and the Giants win 10 games.

Worst-Case Scenario: Coughlin fumbles around the menus and options before frustratingly exclaiming that video games are too complicated and then turning his PlayStation off by unplugging it from the wall.

St. Louis Rams

Ezra Shaw/Getty Images

Key 2014 Results
Record: 6-10 (NFL rank: 23)
Pythagorean Wins: 7.2 (NFL rank: 21)
Pythagorean Difference: minus-1.2 (NFL rank: 29)
Record in Close Games: 3-4 (NFL rank: 18)
Strength of Schedule: 0.502 (NFL rank: 15)
Turnover Margin: minus-2 (NFL rank: 19)

The Rams also made an appearance during Brink Week. These previews sure are easy when you write them weeks in advance! After the season-ending injury to cornerback E.J. Gaines, just about everything else has gone largely as expected for the Rams. Todd Gurley’s on schedule, Nick Foles looks overwhelmed, and the defensive line is going to be terrifying.

One fun thing about the Rams that I missed: They’re going to have an entire side of the offensive line dedicated to rookie linemen. Both the Rams and Bucs will be starting two rookie linemen in Week 1, but Tampa Bay has one (Donovan Smith) at left tackle and the other (Ali Marpet) at right guard; the Rams look likely to start third-rounder Jamon Brown at right guard and second-rounder Rob Havenstein at right tackle. That can’t happen very frequently. If it goes well, the Rams have players who will start for the next four years quickly becoming accustomed to playing alongside one another. If it doesn’t — and the Rams don’t exactly have a great history of developing offensive linemen — Foles is going to hear about it and quick.

Best-Case Scenario: Gurley wins offensive rookie of the year when he runs for 1,400 yards across 13 games, the pass rush destroys opposing quarterbacks, and the Rams benefit from the declining Cardinals and 49ers to go 10-6 and claim a wild-card berth.

Worst-Case Scenario: Both Foles and Gurley get injured, the pass rush fails to cover up the weaknesses at cornerback, and the Rams are abandoned by their fans in advance of a move out west.

Tampa Bay Buccaneers

Cliff McBride/Getty Images

Key 2014 Results
Record: 2-14 (NFL rank: 31)
Pythagorean Wins: 4.5 (NFL rank: 29)
Pythagorean Difference: minus-2.5 (NFL rank: 32)
Record in Close Games: 1-8 (NFL rank: 30)
Strength of Schedule: 0.460 (NFL rank: 31)
Turnover Margin: minus-8 (NFL rank: 26)

Oh, let’s finish with our old friends in Tampa Bay. I wrote about why the Bucs are extremely likely to improve last month, too. That improvement may only end up getting them to 3-13, but hey, that still counts!

Best-Case Scenario: Jameis Winston transforms the Tampa Bay offense, Lovie Smith’s charges coalesce on defense during their second season as they did with the Bears, and the Bucs ride an easy schedule to 10-6 and the NFC South crown.

Worst-Case Scenario: Winston is a turnover machine, Gerald McCoy gets injured, the pass rush never shows up, and Tampa Bay finishes 3-13.

1. Games decided by seven points or fewer.

2. Yes, even better than J.J. Watt, who was at 20.6 snaps per knockdown.