The 5 NFL Teams That Improved Most in 2015

Kirk Cousins helped turn Washington around during his big year. Were they one of the most improved squads in 2015?

When Coach Taylor took over East Dillon's football program, the expectation wasn't that they'd have a winning season right off the bat. It was to be competent, taking one step at a time before eventually reaching some sort of successful season.

If you don't understand this reference, go watch Friday Night Lights.

Coach Taylor's team needed to improve before anything significant was going to happen. And with a bunch of inexperienced players, that improvement was going to come at a slow and steady pace.

It's no different at the NFL level, where teams will have an awfully hard time going from a group of scrubs to a group of stars in just one season. Though the NFL is filled with parity, becoming a Super Bowl champion still takes time.

So with that being said, it seemed like it would be useful to take a look -- analytically -- at which teams saw the biggest improvement from 2014 to 2015 -- to see which teams are headed in the right direction.

To help, I dug into our nERD metric, which determines the number of points we'd expect a team to win by against an average squad on a neutral field. If a team had a nERD of zero, they'd be completely average. If they had a nERD of -3.40, then the expectation would be that they'd lose to an ordinary team by over a field goal.

Got it? Good. Let's take a look at the five most improved teams of 2015.

5. Washington Redskins

2014 nERD: -5.49
2015 nERD: 1.38
Improvement: +6.87

You like that? I know Washington fans do. After a season that saw Washington with a -5.49 nERD, the 5th worst in football, the team jumped up to 1.38, the 14th best total. The easiest thing to pinpoint as to why? Quarterback play.

In 2014, only seven teams ranked worse on a per drop back basis than Washington within our schedule-adjusted Net Expected Points (NEP) metric. This season, Kirk Cousins brought that ranking all the way up to ninth, finishing ahead of every NFC East foe.

Whether they're able to make a run in the playoffs or not, if the boost in passing efficiency can be sustained, then Washington will surely be around next year and beyond.

4. Tampa Bay Buccaneers

2014 nERD: -9.52
2015 nERD: -2.12

A year ago, the Bucs' defense ranked 23rd in the league according to NEP. That spot in our defensive rankings remained the exact same in 2015.

So, naturally, the change here has everything to do with the team's offense. More specifically, Doug Martin and Jameis Winston.

Rushing is a lot less efficient than passing -- while the average per drop back NEP rate for passers was 0.15 in 2015, running backs were fortunate (or skillful) to having a Rushing NEP per rush above zero. 

Doug Martin was unable to reach the 0.00 Rushing NEP per rush mark, but his -0.01 rate was still great for a running back with so much volume. In fact, among the 15 backs with 200 or more carries this season, Martin's efficiency ranked sixth. In turn, the Bucs had the seventh best rushing attack in the NFL, improving dramatically from their 30th-ranked unit last season.

As for Winston, his Passing NEP per pass of 0.13 was below the league average, but it's far above anything the team saw last year, as Josh McCown had a -0.09 NEP per drop back score. In other words, with every quarterback drop back this season compared to last, the Bucs were adding more than one-fifth of a point

If the team's defense can turn it around over the next couple of seasons, the Bucs should be in great shape.

3. New York Jets

2014 nERD: -4.27
2015 nERD: 4.44

The Jets sported the seventh worst defense last season according to our metrics, and with improvements to the secondary, the team was able to jump up and become the sixth best defensive unit in 2015.

Just as big of a reason for their 8.71 nERD increase in 2015, though, was the passing attack. Ryan Fitzpatrick ended the year with a 0.14 Passing NEP per drop back rate, which was 0.13 points better than what Geno Smith saw in 2014. And, if you recall, Smith's numbers are a bit skewed thanks to an insane Week 17 performance.

Fitzpatrick can thank Brandon Marshall for his strong play, as B-Marsh finished with the fifth-best Reception NEP -- points added on catches -- in all of football. And the always-underrated Eric Decker was NEP's ninth-best wide receiver in 2015.

2. Carolina Panthers

2014 nERD: 0.49
2015 nERD: 9.26

We shouldn't be all that surprised to see the Panthers, who went from being a seven-win division winner to a 15-1 powerhouse in just a single season, on the list. The defense was strong across the entire season this year -- only the Broncos were better -- whereas last season saw a late surge from the secondary. 

Naturally, the reason for Carolina's big jump is because of the probable league MVP, Cam Newton. Last year, Cam compiled just 18.40 Passing Net Expected Points (granted, he played 14 games) and a 0.04 Passing NEP per drop back. If you remember, this was with rookie Kelvin Benjamin as his top wideout. 

This year, Newton's Passing NEP total is 105.04, and he increased his efficiency by a factor of five, all the way to 0.20. And this came after losing Benjamin in the preseason.

Though there are a handful of quarterbacks who put up better Net Expected Point totals, the improvement shown by Newton and the result it placed on the Panthers is the main reason he's probably going to be this year's league MVP.

1. Arizona Cardinals

2014 nERD: 0.70
2015 nERD: 13.11

The Cardinals were lucky in 2014. They won 11 games and were an above-average team, but they were lucky -- just about every close game they played, they ended up winning.

Their 11-5 record last season wasn't indicative of how good of a team they were, as shown by their 0.70 nERD.

This season, you could argue the opposite is true. Yes, Arizona won 13 games -- which was more than all but one team -- but they've did so in crazy-good fashion, ending the year with a 13.11 nERD. To give you historical context, only the 2007 Patriots (19.08 nERD), the 2001 Rams (14.46) and the 2007 Colts (13.14) have had better nERD scores since the turn of the century.

Like most of the teams here, a huge credit to this improvement goes to Carson Palmer, who led the NFL with a 186.49 Passing NEP total. And because of Palmer, the Cardinals, according to our numbers, are the most dangerous team in this year's playoff.