In the stock market, they call it "diversification."
The theory: Instead of investing all your money into one asset, you spread money over a number of different investments. It is proven to be one of the most cost-effective means to create the potential for high returns while minimizing the risk of losing it all in one fell swoop.
In the NFL, they call it the "running back by committee" (they also call it "a fantasy football GM's worst nightmare").
The theory: Instead of one feature back who is forced to do everything, teams carry a number of specialist backs. With three or four options, a team can be prepared for anything, be it game situations or injuries—which are all too common for running backs.
Diversification has made a notable impact on the value of the running back position. The last time a running back was taken in the first round of an NFL draft: 2012 (Alabama running back Trent Richardson, drafted third overall by the Cleveland Browns). Before 2012, the last time a running back wasn't taken in the first round of a draft: 1963.
Teams are now aiming to round out their depth charts with a bevy of backs. Whichever one is best suited to answer the bell in any situation is the one who trots onto the field.
Some offensive systems value some kinds of running backs higher than others. Some backs fill multiple roles for their team, others have carved out their niches. For any team to have a successful stable of backs, though, they should have at least one back who can fill each of these roles.
Every backfield needs a leader. This player is the one who gets the majority of the snaps and can probably be spotted on the field on first down.
These backs must have a few qualities:
- Vision to find holes in the offensive line
- Burst to hit those holes and gain positive yards
- Endurance to play a majority of the team's offensive snaps
- Ball security
Sources: ProFootballFocus.com, SportingCharts.com
The above list of backs represents the league's top 20 in carries alone. Houston Texans running back Arian Foster could also be added to a hypothetical list of "bell cows," but he played only eight games last season. Other backs who could be in the debate for bell cows are Carolina Panthers running back DeAngelo Williams and New England Patriots running back Stevan Ridley.
Other traits can be argued to belong in this mix, but those will be outlined below and can all be applied to specific styles of backs. Regardless of style, a back should possess the above traits in order to be successful in a primary role.
Short-Yardage (Power) Back
These guys do the dirty work.
Every team needs a big back with the vision to find holes, the strength to break tackles and keep those legs moving for extra yards, and ball security to prevent untimely fumbles in big spots.
|Play type||Plays||First downs||Touchdowns||Conversion %|
Overall, converting short yardage was a more successful bid on the ground than it was through the air. There's nearly a 13 percent disparity between the ability to convert short-yardage situations on the ground than through the air.
Admittedly, this stat is in a vacuum, and nothing in the NFL happens in a vacuum. The NFL may be leaving its roots behind, but we still cannot underestimate the value of a running back who can plow his way forward (and offensive linemen who can clear the way for him).
Besides, sports work in cycles, and as defenses continue to load up on lighter, faster defenders to stop the pass, smart offensive coaches will again adapt their game to incorporate more power-running elements.
3rd-Down ("Scat") Back
It's a passing league.
Those four words have been a thorn in the side of every running back for years.
As a result, we've begun to see a surplus of backs who excel on passing downs. Most often, these backs feature a blend of soft hands, good instincts in pass protection, speed to break long gains on screens and quickness to "pick" their way through a defense on delayed handoffs and draw plays.
Running backs like Darren Sproles and Danny Woodhead have made careers out of their ability to contribute in various ways when the team wants to pass. Sproles was not asked to pass-block nearly as much as Woodhead, but Sproles spent many of his passing downs lined up as a receiver flanked out wide.
A good scat back can sometimes be a team's most valuable weapon. Woodhead was the Chargers' second-leading receiver with 76 catches, just one short of the team-leading 77 by tight end Antonio Gates. Sproles ranked in the top four in receptions for the Saints each year with the team (2011-2013).
Diversification Within Diversification
NFL teams want to major in specialization and diversification in their offensive backfield, but there are pitfalls to such a strategy. For one, a defense can get a feel for what an offense is trying to accomplish if a running back only ever enters the game in specific situations.
Take LeGarrette Blount, for example. Blount played 289 regular-season offensive snaps, according to Pro Football Focus (subscription required), and carried the ball 153 times (52.9 percent of his snaps resulted in him taking a handoff).
It didn't matter when the New England Patriots were running roughshod over shoddy run defenses like those of the Buffalo Bills (ranked 28th, allowed 267 yards vs. the Patriots) or Indianapolis Colts (ranked 26th, allowed 234 rushing yards vs. the Patriots).
The Patriots ran into a brick wall when the Denver Broncos' seventh-ranked run defense stifled their running attack to just 64 yards in the AFC Championship game, mostly by loading up the box every time Blount was on the field, thereby forcing Brady to audible and take Blount out of the picture.
It's important to cover all the bases in building a well-rounded backfield, but it's helpful if one or some of those backs can cover multiple bases on their own. Defenses are always looking to gain an edge, and if they know what's coming based on what running back enters the game, the offense is already at a disadvantage before the ball is even snapped.
Draft vs. Free Agency
Team-building at running back is a tricky topic. NFL teams don't seem too thrilled about the prospect of investing any resources in backs these days. As mentioned above, there hasn't been a running back drafted in the first round in the past two years.
According to Spotrac (subscription required), the average contract for a running back in 2013 came in at 1.94 years and around $2.2 million per year. At that rate, you could have a roster of 53 running backs and still not hit the $133 million salary cap. A total of 18 veteran free-agent running backs signed deals this offseason.
The average age of a running back to sign a contract this offseason was 26.8 years old, but a recent study by Kevin Seifert of ESPN.com indicates the ages of 25-27 are prime time for an NFL running back.
Teams are not leery of signing older veterans, but Seifert's study seems to fall in line with the recent trend of targeting younger backs in the draft.
The average age for an NFL running back in 2013 (min. one carry, 150 qualifying backs) was 25.69 years old. Even with a minimum qualifier of 60 carries (62 backs), the average age is still 25.39 years old. That seems to indicate that teams would much rather take their chances on a young back in the draft than gamble on an aging veteran in free agency.
As is the case with diversification at the running back position, so it is also the case with how those running backs are acquired.
Good Examples of Well-Rounded Backfields
The NFL's best backfield may currently belong to the Philadelphia Eagles.
With the 2013 rushing champion and all-purpose-yardage leader LeSean McCoy backed up the by all-purpose dynamo Darren Sproles and a pair of young bruisers in Chris Polk and Matthew Tucker, the Eagles have diversified their portfolio in the smartest way possible.
Eagles head coach and offensive whiz Chip Kelly is probably already running out of ink from writing down all the ideas on how to use Sproles. Bleacher Report's Brad Gagnon broke down some of the ways the Eagles can get the most out of Sproles:
We know Kelly loves players who can line up in multiple spots and produce from wherever they're situated. ... And don't think the Eagles won't use plenty of two-back looks with McCoy in a standard spot and Sproles lining up somewhere to give defenses fits.
Sean Payton is quite an offensive mastermind, but now Kelly gets his hands on Sproles. The Eagles love their packaged plays, so look for that and many other elements to be added to Sproles' game in 2014.
Adding Sproles to the equation not only opens up a wide range of new options for Kelly by adding a dynamic scat back to the equation but also gives the Eagles a solid backup in the event that McCoy goes down with an injury. The presence of both Polk and Tucker on the roster gives the Eagles two options for short-yardage situations.
Not every team can have the NFL's leading rusher on their roster, though.
Another good example of a well-rounded backfield is the Cincinnati Bengals. They don't have quite the depth of other backfields, but their one-two punch may be one of the best the league has to offer. The two backs split the touches almost exactly 50-50: BenJarvus Green-Ellis had 224 (220 carries, four receptions) and Giovani Bernard had 226 (170 carries, 56 receptions).
Green-Ellis remained the top option for short-yardage carries (44 to Bernard's 23), while Bernard was the clear favorite on passing downs (315 passing snaps to Green-Ellis' 154) due to his pass-blocking and receiving ability.
Several fans and analysts were taken aback by the team's selection of running back Jeremy Hill in the second round, but an injury to either Green-Ellis or Bernard would put the rushing attack in serious jeopardy. Plus, with Green-Ellis entering a contract year (and getting closer to that magic age of 28), the Bengals now have insurance against his potential departure.
Plenty of other teams have struck a balance in their backfield to incorporate a variety of skill sets—and subsequently, a variety of different ways to make plays at the running back position.
Diversification. That's the name of the game for an NFL roster trying to build the most successful backfield possible.
Snap data provided by Pro Football Focus' premium section.
Erik Frenz is also a Patriots writer for Boston.com.