Can Jonathan Stewart Really Be a Top Running Back in Fantasy Football This Year?

It feels like we've been waiting for this for over a decade. Jonathan Stewart, after years of injury and sharing a backfield, is now injury free and DeAngelo Williams-less.

It's about damn time.

Because of this, expectations are fairly high. In fantasy football terms, early drafts indicate that J-Stew is looking like a firm RB2 for teams in 10- or 12-team leagues, making him a top four or five round pick.

At the surface, it all seems to make sense. The Carolina backfield is pretty vacant, with not a ton of competition for touches. The offense, too, just added a new weapon in Devin Funchess, will have Kelvin Benjamin for his second season, and has one of the better starting quarterback situations in football with Cam Newton.

What's there not to like with Jonathan Stewart?

J-Stew's 2014 Campaign

Jonathan Stewart had pretty good raw numbers last year. On 175 carries in 13 games -- the most he's had since 2010 -- he rushed for 809 yards and 3 touchdowns, good for a 4.6 yards per carry average. That 4.6 rate was the best he's seen since his 2011 campaign. Stewart also added 25 catches for 181 yards and a score through the air.

If we want to play the extrapolation game, over 16 contests, Stewart would have hypothetically amassed about 215 rushes for nearly 995 yards and 3.69 touchdowns on the ground last season, while snagging 31 receptions for 223 receiving yards. All together, in PPR leagues, that's a little over 182 fantasy points, which would have ranked just outside the top 10 last year.

But we all know extrapolation isn't the smartest way to produce fantasy football outlooks. Instead, we can look at numberFire's signature Net Expected Points (NEP) metric to see how J-Stew really performed on the field last year, and see if he's for real or not. (You can read more about NEP in our glossary.)

In 2014, 32 NFL running backs ran the ball 150 or more times. In terms of cumulative Rushing NEP, Jonathan Stewart ranked 22nd in this group with a -9.87 Rushing NEP score. This was the same rank he had on a per rush basis among this cohort as well.

Don't be alarmed by the negative score here -- rushing is less efficient than passing, so many high-volume backs have Rushing NEP totals under zero. However, the rank is important. Players like Terrance West, Chris Ivory and Steven Jackson added more points for their teams last year on the ground, per NEP, which isn't the best endorsement for J-Stew.

Admittedly, I was pretty surprised by Stewart's lack of NEP love given his strong yards per carry average, so I dug a little deeper. What I found was that this could be a case where the expected points algorithm dinged him heavily due to game situation.

Take a look at Stewart's splits last year on first, second and third down, per ESPN.

With an expected points model, a player is going to appear more successful -- more valuable -- if he's accumulating production when his team needs him most. In other words, if it's 3rd-and-15 and Peyton Manning gained 13 yards, that's not as valuable as a 3rd-and-2 where Manning gains 3. One results in a punt, and the other results in a first down.

As you can see from the numbers above, Stewart excelled on early downs, which are naturally weighed less than late ones. This is simply due to the fact that the change in expected points on a first-down run will be smaller than on a third-down one.

The other thing to note is that Stewart lost one fumble last year, and that fumble came on his opponent's goal line. That's more than likely a shift of about five expected points, which can dramatically change a running back's average.

That's why the important thing about Stewart's advanced metrics -- to me, at least -- is his Success Rate, which measures the percentage of positive plays a player makes in terms of NEP. It's a binary way of looking at a player -- if he makes a good play, it's deemed a success. If he doesn't, it's not.

Going back to that group of 32 running backs with 150 or more carries, Stewart's Success Rate actually ranked 12th last year, ahead of players like Justin Forsett, Eddie Lacy and Arian Foster. Because of the aforementioned decline on later downs last season, along with his costly fumble, this seems to be the reason to be excited about his 2015 potential, as long as he's healthy.

But don't go drafting him just yet. There's still something important that could cap his ceiling.

A Lack of Upside?

If you draft a player in the first four or five rounds of your draft, you're not just hoping he lives up to that draft slot's potential. You want your player drafted as an RB2 to finish as an RB1. You want all that you can get from your draft selection.

That upside could be a problem for Stewart.

Over the last three years, only five fantasy running backs in PPR leagues have finished in the top 10 at the position while scoring fewer than eight rushing touchdowns. The list of those players is below.

Naturally, something else had to bolster these players in order for them to finish as top-10 backs. That something is receiving ability -- each of them caught at least 35 passes out of the backfield, scoring at least once.

Why bring this up with Stewart? Because there's a good chance he doesn't come close to eight rushing touchdowns this season. With Cam Newton under center, the Panthers simply haven't scored many rushing touchdowns with their running backs.

No back over the last four years has hit the eight touchdown mark in Carolina. And while things are a little more defined in this year's backfield, the team still has two goal line weapons in Cam Newton and Mike Tolbert to compete for those rushes.

Not only that, but with Cam Newton quarterbacking, the Panthers have been the third run-heaviest team in the NFL (spans the last four years combined) in the red zone. While that may appear as an opportunity, what it really shows us is that there's not much room for growth for a running back in that system. What we've seen might be what we get.

So if Stewart doesn't hit the eight rushing touchdown mark, he would need to make up for the difference -- in order to be a top-notch fantasy running back -- through the air. Maybe that's possible -- in 2011, Cam Newton's first season, Stewart caught 47 passes out of the backfield, scoring once. He's barely hit that total over his last three seasons combined though (28 games), and since that year, no Carolina running back has hit the 40 target mark.

2015 Outlook

For Stewart to become a top-10 fantasy running back, it may be difficult. But that doesn't mean he won't be a worthwhile fantasy selection.

As long as Stewart is healthy, his floor appears to be pretty high -- he'd be a virtual lock to hit the 200-carry mark in what was an average NFL offense last year. Ideally, though, running back-heavy fantasy teams should look for him to be their RB3 rather than RB2, just to factor in the injury risk and lack of touchdown upside.