Prior to their December 7th contest in New Orleans, the Carolina Panthers had won three games in 2014.

They're now hosting a playoff game on Saturday.

The Panthers lost their eighth game of the season in Week 13, dropping to the Vikings 31-13 in Minnesota. After the conclusion of that week, Carolina, according to our metrics, had just 4.3% odds of making the playoffs. Those odds were essentially the worst of any team with a mathematical chance of making it -- the Browns were sitting with a 12.7% chance of making the postseason at the time, while the Bills had a 17% chance of getting in, just for reference.

Sure, the NFC South was perhaps the biggest dumpster fire of a division we've ever seen, but the improbable run that the Panthers just went on still can't be ignored. How in the world did it happen?

The Defense Is Back

The Panthers closed out 2014 on a four-game winning streak, and during this stretch, the team held opponents to just a little over 10 points per game. While two of those opponents were the Browns and Buccaneers -- offenses that rarely move the ball effectively, ranking 28th and 31st offensively according to our Net Expected Points (NEP) metric -- the other two were top-10 units (Atlanta and New Orleans).

After Week 13, Carolina's defense ranked 21st in the NFL according to our schedule-adjusted numbers. Now, the unit ranks 10th.

This jump in ranking is pretty insane considering it happened over a four-week stretch. To give you some perspective, the team's raw, non-adjusted Defensive NEP after Week 13 was 93.18. This tells us that, had the Panthers played relatively average defensively, they would have prevented roughly one additional touchdown (7.8 points) per contest. "Average" nowadays isn't exactly zero, but their raw score was really not good.

After yesterday's game, the Panthers' Defensive NEP had dropped to 54.93. That's a 38.25 swing in four weeks, or -9.56 Defensive NEP per game. The best average Defensive NEP per game this season -- a reminder, this is not adjusted for strength of opponent -- came from Houston, who played 4.39 points above expectation per contest. Naturally, it's impossible to play at an incredibly high level week in and week out, but the fact that Carolina's played more than twice as effectively as the best defense in the NFL over the last four weeks is more than impressive.

The offense, too, has improved during the team's winning streak. After their loss to the Vikings in Week 13, the Panther offense ranked 26th in the NFL in Adjusted NEP. Though the increase in rank hasn't been as dramatic as it was on the defensive side of the ball, the team's overall offense has jumped to 18th over the last four weeks. Combine that with a defense playing as well as any other in the league, and you've got the perfect recipe for a winning streak.

Carolina's facing an Arizona Cardinals team this weekend that's understandably been struggling due to their quarterback situation. As 4.5-point favorites, the Panthers have a great opportunity to move on to the Divisional Round. And although they won just seven games this year, we all need to recognize them as a legitimate threat in the NFC. The defense is playing just as well as any other unit, and the offense has improved as well.

Who would've thought?