Ranking the 8 Defenses Remaining in the 2015 NFL Playoffs

With the divisional round of the playoffs approaching this weekend, which defenses are best equipped to get their team to the next round?

Ben Roethlisberger's shoulder. Peyton Manning's foot. Aaron Rodgers' significant other.

These are the main stories dominating headlines as the NFL playoffs enter the divisional round. Team success is heavily dependent on the quarterback, so it makes sense to focus on these guys when there may be some doubt about their potential level of performance.

But let's hold up just a second here, y'all. Aren't we forgetting something? Yeah, the quarterback is important, but if you have the tools to neutralize the opponent, that would seem to be equally noteworthy.

With this in mind, let's look at the defenses remaining in the playoffs and see which is most prepared for success. We'll do so using numberFire's Net Expected Points (NEP). This is the metric we use to track the efficiency of both teams and players, with the team side being adjusted based on strength of schedule.

Before each play, there is an expected number of points that the offense will score on its current drive. A positive play (when they pick up a first down on 3rd and short) will increase that, resulting in positive NEP. But if they get stuffed on 3rd and 1, their expected point total for the drive will decrease, resulting in negative NEP.

To rank the defenses, we'll use Adjusted Defensive NEP per play. This basically tracks the ability of the defense to prevent the opposing offense from increasing its expected point total. We'll break it down both against the pass and the rush, but the rankings will start with the overall look.

When I list the "Overall Rank" and then the rankings against both the pass and the rush, those will be out of all 32 teams. This can give us a better idea of the tiers that exist and the distance from one unit to the next than simply ranking them first through eighth would.

Quarterbacks are important, but so are the guys trying to stop them. Which defenses are most equipped to do so? Let's take a look.

1. Denver Broncos

Overall Rank: 1st | Pass Defense Rank: 1st | Rush Defense Rank: 5th

The Denver Broncos will serve as an interesting test on the importance of defense in the NFL playoffs. They were first on defense, but they finished 28th in Adjusted NEP per play on offense. That is a hefty, hefty margin.

They could catch a bit of a break with both Antonio Brown and DeAngelo Williams appearing doubtful to play this weekend. Brown gashed the Broncos' secondary for 189 yards and 2 touchdowns in Week 15, and Williams was third in Rushing NEP per carry. The Broncos allowed only three wide receivers to top 100 yards against them this year, and a Pittsburgh Steelers offense without Brown would only give a boost to an already dominant Denver defense.

2. Carolina Panthers

Overall Rank: 2nd | Pass Defense Rank: 2nd | Rush Defense Rank: 11th

So, the Carolina Panthers have the guy who will likely be the league's MVP in Cam Newton, and their defense is the second best in the league? I guess that'll work.

A look at the rushing defense ranking of 11th could be a bit deceptive. Luke Kuechly was out from midway through Week 1 until Week 6. At the start of Week 6, they were 27th against the rush, but they climbed the board steadily after that. This could make things difficult for Marshawn Lynch if he, indeed, is able to return this week.

It's the pass defense that could stand the biggest task this week. Russell Wilson's hot end-of-season streak landed him third in Passing NEP per drop back, but the Panthers limited him to 3.79 Passing NEP on 30 drop backs in Week 6. If they can do so again, they'll have a good shot at playing for the NFC championship.

3. Seattle Seahawks

Overall Rank: 4th | Pass Defense Rank: 5th | Rush Defense Rank: 6th

This is going to be a stupidly fun game.

The Seahawks were the only team other than the Broncos to finish in the top six both against the pass and the rush. The Panthers were the ninth most efficient passing offense and fifth on the ground. Again, this is going to be sweet.

As the Panthers did to Wilson, the Seahawks held Newton in check in Week 6. He finished with 3.66 Passing NEP on 36 drop backs, though he did add 2.09 Rushing NEP. That's far less than he was able to do against most other defenses from then on out. Sunday can't get here soon enough.

4. Kansas City Chiefs

Overall Rank: 5th | Pass Defense Rank: 4th | Rush Defense Rank: 8th

You saw this on full display last week as the Kansas City Chiefs ripped Brian Hoyer and the Houston Texans to shreds. That wasn't because the Texans came from the lackluster AFC South; it was because the Chiefs are legit.

This won't make things easy for Julian Edelman in his return to the New England Patriots. The Chiefs did allow seven different wide receivers to top 100 yards this year, but only two of those came after Week 7. This is a defense that improved dramatically after their bye week, and the Patriots will face a stiff challenge on Saturday.

5. Arizona Cardinals

Overall Rank: 7th | Pass Defense Rank: 8th | Rush Defense Rank: 2nd

Allow us to bring you back to Week 16, when the Green Bay Packers made the trek to the desert to face the Arizona Cardinals. In that game, Aaron Rodgers had -24.7 Passing NEP on 28 drop backs; the team lost almost an entire expected point every time he dropped back to pass. Yowza.

The big concern here, though, is the absence of Tyrann Mathieu. Mathieu was also out for that Green Bay game, but then Russell Wilson dropped 13.29 Passing NEP on the Cardinals in Week 17 on just 28 drop backs. Their current level is likely somewhere between their Week 16 and Week 17 performances, but being without one of their defense's key members is a reason for pause.

6. Pittsburgh Steelers

Overall Rank: 9th | Pass Defense Rank: 9th | Rush Defense Rank: 4th

The Steelers' defense gets a bad rap for the seemingly constant involvement in shootouts, but in terms of efficiency, they truly weren't bad this year.

If the Broncos' offense wants to find success against these Steelers, they'll likely need to do so with Manning's arm. Only five different running backs had at least 70 yards against the Steelers this year, and they held Ronnie Hillman and C.J. Anderson to a combined 18 rushes for 60 yards (3.33 yards per attempt) and -6.07 Rushing NEP. In Peyton we trust?

7. Green Bay Packers

Overall Rank: 11th | Pass Defense Rank: 10th | Rush Defense Rank: 26th

The Packers are ranked seventh on this list, but they were still 11th overall. On the whole, they weren't really too bad. A meeting with David Johnson, though, isn't likely to help those numbers.

Johnson led the league this year in Rushing NEP per carry among those with at least 100 carries, and the Packers finished 26th against the rush. When they met in Week 16, Johnson turned just 12 touches into 127 yards from scrimmage, a touchdown, and 8.59 Total NEP. With the Cardinals favored by seven, this one could get ugly if the Packers can't bottle him up early.

8. New England Patriots

Overall Rank: 12th | Pass Defense Rank: 15th | Rush Defense Rank: 12th

Most of the discussion around the Patriots recently has centered around their battered offense. That's certainly something to monitor, but they also have the lowest-ranked defense remaining in the playoffs. That could be bad.

One thing that will work in the Patriots' favor, though, is that they match up well with the Chiefs' passing offense. The Patriots were 15th against the pass, but the Chiefs were just 19th on the offensive side. If Jeremy Maclin can't go because of his high-ankle sprain, that could permit the Patriots to forge onto the next round despite not having the most stout defense of the bunch.