The NFC South, since its inception in 2002, has long been the ficklest of NFL divisions. From 2002 to 2013, there had never been a divisional champion two seasons in a row. That all changed in 2014 though, when the Carolina Panthers surged to win their final four games and, with multiple strokes of luck, became the second team in NFL history to win their division with a losing record.

By most NFL analysts’ estimations, the NFC South shouldn’t have been as bad as it was last season. But Carolina’s defense was the only one in the division that finished as a top 20 unit according to our numbers, and even that was only because they really gelled in the final half of the season.

To look at where these teams may be headed, I'll take a look at the data on the offensive and defensive sides of the ball using numberFire's signature metric, Net Expected Points (NEP), in order to get a baseline for where the teams were when we last saw them, and how their 2015 squad might improve upon or regress from that baseline. The basics of NEP: it calculates how an individual player, or team in this instance, performs above or below expectation based on a host of football variables. You can learn more about NEP here in our ProFootballFocus.

The result was that the Bucs raced to a woeful 2-14 finish in Lovie Smith’s first season as head coach.

Soon after season's end, they set about hiring former Falcons' offensive coordinator, Dirk Koetter, as their offensive coordinator. You might remember that Koetter's offense beat the brakes off of the Falcons to the tune of 56-14 last season. Lovie Smith wanted that kind of offensive mind on his squad, and he got him.

The bright side for the Bucs is that this terrible season allowed them to land Florida State quarterback, Jimmy Graham to the Seahawks in exchange for All-Pro center Max Unger and a first-round draft pick.

They also let go of pass-catching running back Pierre Thomas for a younger, more explosive -- and equally capable pass-catcher -- in C.J. Spiller, who figures to occupy the former Darren Sproles role. Finally, the team also traded away the most efficient wideout over the past two seasons in Kenny Stills in efforts to help beef up their defensive unit.

The big question for the Saints offense is whether Drew Brees can maintain his elite production with a rather depleted arsenal of weapons. Brees managed to help the Saints compile the seventh highest Passing NEP in the league last season, and while he still put up top 10 numbers in terms of per drop back efficiency (0.17 NEP per pass), last season was his third lowest per-pass average since coming to New Orleans.

The return of Brandin Cooks should help, and third-year pro Nick Toon should get some chances to make some noise with Stills gone. And, of course, the ever-reliable Marques Colston still remains as a familiar face for Brees to connect with.

There were unsubstantiated rumors swirling around this offseason about Brees being on the trade block due to the massive salary cap hit the Saints will take the next two seasons under his deal. And the Saints even brought in rookie quarterback Garrett Grayson to be Brees’ understudy, so it appears that the Saints have at least begun to prepare for the future.

But for now, the Saints are hoping that Brees, as he has since he arrived in New Orleans in 2006, will continue to keep the Saints in contention by continuing to elevate the play of those around him.

Defense

Using Adjusted Defensive NEP as our guide, New Orleans brought the worst defense to the field in the entire league in 2014, both in terms of volume and per-play defensive production. As such, it'd be an understatement to say that Rob Ryan’s job as defensive coordinator resides in a seat as hot as the surface of the sun.

The Saints didn’t stand pat, however, and added numerous pieces to help make Ryan’s job a bit easier.

Ranking 31st in overall pass defense last season, the Saints added two-time Super Bowl champion cornerback, Brandon Browner, into their mix. Browner, coupled with Keenan Lewis, should serve as a formidable duo on the outside. The return of Jairus Byrd, who went down after a disappointing four games last season, should help shore up the Saints secondary as well.

In the Kenny Stills trade, the Saints brought in veteran Dannell Ellerbe, whose best days were likely left behind in Baltimore after a really disappointing season with Miami. But the team also used considerable draft capital to improve their linebacking corps, bringing in first-round pick Stephone Anthony to start at inside linebacker and Hau’oli Kikaha to play outside linebacker.

In Anthony, the Saints hope his size and athleticism will lead to immediate contributions in run stopping and in the short passing game. Stopping the run is critical to New Orleans finding success; like the passing game, they ranked 31st in Adjusted Defensive Rushing NEP per rush.

Kikaha figures to get more playing time than the Saints had planned for early, as last week due to the contentious release of Junior Galette, whose off-the-field issues became too much of a headache for the team. Galette’s pass rush skills will be sorely missed, and how fast Kikaha can get up to speed to fill some of that void is a big question mark.

With a likely improved secondary the Saints may be able to better absorb the loss of Galette’s pass-rushing abilities, but this will require a return to 2013 form for newly resigned defensive end Cameron Jordan, whose sack total dipped from 12.5 to 7.5 from 2013 to 2014.

Conclusion

If the Saints can manage to piece together a middle-of the road defense with their new additions, then Brees’s talent may be able to take them to the top of the NFC South mountaintop once again.

Projected Record: 8.5-7.5
Division Probability: 35.5%
Playoff Probability: 50.3%

The Battle for the NFC South

With a tenuous two-year grasp on the division title, the Panthers will need their defensive unit to return to the 2013-version, and Superman Cam to be fully healthy to take full advantage of the towering weapons at his disposal.

The Falcons have significantly upgraded their defensive unit so that their offense doesn’t need to score 30-plus points per game to get a win; something that they are still capable of doing. The Saints have re-orchestrated their offense to reflect more of a balanced approach while adding youth and experience on the defensive side of the ball, which they are confident can return them to Super Bowl form. And the Bucs have upgraded their offensive line and added the most sought after quarterback in the draft since Andrew Luck.

This division figures to be an exciting race to the finish line in 2015, but less in the race-to-the-bottom way it existed as in 2014. As such, expect close, heated matchups, particularly as the regular season draws to a close, because the NFC South is up for grabs.