Running Backs have lost some luster in fantasy circles in recent years. “Zero RB Theorem” proponents abound and it is now entirely possible to see fantasy drafts occur in which a running back isn’t even taken in the first round.
I expounded on why this may very well be the new norm in two of my favorite pieces entitled “The Death of the Fantasy Running Back, and How We Can Save the Position from Extinction” and “Doomsday! Why Fantasy Running Backs Are Even Worse Off Than We Feared”.
However, I don’t think it is enough to point out that the position is in decline or that signs like decreasing rush attempts and rush yards are becoming much more obvious year over year. What is needed is a way to really examine how valuable each top running back is to their respective teams. In essence, are we drafting running backs simply because they are a starter or does the player clearly bring added value as a rusher to the team he’s on?
At first glance is this a fairly nebulous question. It might even seem subjective depending on who you ask, or even which player you ask about. But what if we broke it down using the great data set from NFL Savant?
What needed to happen first was I needed to find out each team’s rushing tendencies. How often did they rush to each hole? How much yardage did they gain on average? Here are the team level results:1
Great data to be sure, but let’s break it up into two separate data sets — one that looks at some of the heaviest used running backs on their own, and another that looks at how each team performed without that specific back — in order to try to determine a player’s rushing value relative to his surroundings.
Breaking Out the Highest Volume Rushers
In order to achieve this we first must determine which players we want to evaluate. I chose all running backs with over 100 rushing attempts last season which gave me a list of 45 players. This allows for teams which utilize a running back by committee approach (RBBC) and teams which saw their lead running back succumb to injury mid-season. This produced the following two tables:
It is fascinating to see how teams depend on certain players to play very specific roles in their offense and whether that dependence is advantageous for the team or not. If we combine these two charts, we can actually determine the average impact, either good or bad, these running backs have on their team’s offensive production with the ball in their hands. In order to determine this we need to figure out the difference between carries in which one of the running backs listed above carried the ball and when another player on their team carried the ball. When doing this we get the following table:((Note: In order to minimize the impact of any one rush, either good or bad, I omitted values where the hole in question was less than five percent of each team’s total rushes. These instances are denoted by blank cells in the table below.))
Before I get into some conclusions, here is the breakdown of the volume of attempts for each hole by percentage, which shows the strength of the samples for each specific hole above, and which were omitted.
Which Backs Rose Above Their Teammates?
I’ve inundated you with a lot of information thus far but here is where everything comes together. To find out the added value (or in some cases, lost) that a specific player contributes to his team on any given rush play, we use the team percentage breakdown to weight the net effect of each with-or-without-you sample by volume. This allows us to put a single number to the value added or lost for a specific RB, relative to the other RBs on their team, for an average rushing play. Here are both the unweighted and weighted results, for comparison:
Here we are, the payoff for all the hard work. Intuitively, much of this make sense when you think about it.
Notably Poor Performers
Starting with players who cost their teams value, we are drawn immediately to Arian Foster. Foster had an atrocious ground game last year, albeit in only four games. What really hurt Foster in this evaluation was how poorly he did when rushing to the left tackle. Foster consistently lost yardage when running to this hole, averaging -2.00 yards per carry while his teammates averaged 4.55 yards per carry to the same hole.
This was compounded by the fact that the Texans rush to that hole somewhat regularly with 12 percent of all of their rushes headed that way. In fact, Foster only showed marginal improvement over his teammates at two holes — left guard and center.
Another player who negatively impacted his team was Chris Johnson, who could be expected to gain nearly a full yard less than his teammates on any given rushing play. Johnson’s issue was spread fairly evenly across the left side of his offensive line where he gained, from the outside in, -1.15, -3.63, and -4.81 yards to the various left side holes in comparison to his teammates. He also gained -2.74 yards to the right end, which is concerning when Johnson’s game is primarily focused on speed to the outside.
The final player who stood out was Marshawn Lynch. Long an extremely dependable rusher, Lynch, on the surface, appears to have broken down last season. However, his contribution appears worse than it actually was due to how well Thomas Rawls performed in his absence. Lynch, had a positive average for every location and gained roughly two and a half yards when rushing to every hole but the left end. That’s nothing to sneeze at, but this analysis suggests he may have left some yardage on the field as Rawls outgained him handily in all but the center and right guard holes.
This brings us to players who significantly contributed to their teams. The first player is the one I just finished mentioning, Thomas Rawls. While I’ve outlined much of his success as a counterweight to Lynch’s contribution, Rawls’ contribution to Seattle’s rushing attack can’t be overstated. Rawls contributed more to his team, in comparison to other rushers on his team, than any other of the 45 top running backs in the league. He could be depended on to add 1.75 yards more than his teammates. That amount is substantial and, when compared to the average contribution for the 45 top running backs, Rawls gains over a yard and a half more for his team than your average top running back!
Another player who was extremely valuable was Dion Lewis. Lewis gained roughly a yard and a half more than his teammates, namely LeGarrette Blount. Lewis’ biggest contribution came on rushes that attacked the left guard where Lewis gained 8.50 yards per average against 3.38 yards per carry by non-Lewis Patriots to the same hole.
Finally, the third biggest contributor of the 45 running backs listed, Ryan Mathews added 1.34 yards of value per carry. Mathews’ situation is almost the exact opposite of Lynch’s. In this case, Mathews looks better than he actually is because of how underwhelming DeMarco Murray was, and where Murray was actually above average (right guard), the Eagles barely ever ran to that hole (six percent of all rushes).
- Please Note: The holes listed below are how rushes are signified in play by play data. The labels refer to the hole to the outside shoulder of the listed position. In the case of the Center it refers to the holes on both sides of this position, hence the greater number of rushes to this area. (back)