How Offensive Lines Impact Fantasy RB Production

Football games are won in the trenches, and fantasy football matchups are won with a solid RB (or two). We’ve all heard the saying “running backs don’t matter”, so if that’s the case, what should we look for when attempting to pinpoint a stud in our drafts? Typically, we look at a team’s offensive line to decide between players in the same tier, or even when looking to have a player jump a few spots up our rankings, but how much does line play really impact an RB? Let’s take a look at what level of offensive line play the top five fantasy running backs were exposed to in each of the past 10 seasons, in terms of their offensive line’s end-of-season ranking. 

A lot to take in, I know. To summarize: I took the top five backs (based on FFToday’s half-PPR format) each year since 2009 (a 10-year sample) and saw where PFF graded their team’s run-blocking unit by season’s end. From 2009-2015, PFF listed the team’s run blocking grade, which I used for those seasons, but beginning in 2016, they just listed the overall grade, so I used that from then on out. This may have impacted the numbers since some teams are elite at run-blocking but struggle in pass protection (example: the Chargers ranked 5th in adjusted line yards but 13th in adjusted sack rate, per Football Outsiders), but that’s what I’ve got, so we’re going to roll with it.

As you can see from the table on the left, a good bit of the most productive running backs each year were running behind an “average”, or better, line. Since there are 32 NFL teams, we will define “average” as ranking between 13 and 19 (+/- 3 from 16), therefore above-average is the top 12 teams, and below-average is the bottom 12. Using this definition, we can see that over the last 10 seasons, there were only 13 occasions (or just 26% of the time) where a running back behind a “below-average” line finished top five. Now, this may be a bit subjective, but in these instances, the backs who did overcome running behind a below-average line, were elite. Barring Lamar Miller, Doug Martin, and Peyton Hillis, every other back could be lumped into this category of being an upper-echelon talent.  Yes, even Frank Gore (12 seasons with > 1,200 YFS). 

This leads me to believe that if a player has the talent, and their offensive line isn’t in complete shambles (2018 Cardinals), then that running back will still be able to overcome this obstacle and produce (as we have seen from AP, Marshawn Lynch, Jamaal Charles…). Despite this belief, it’s hard to deny there is some correlation between fantasy finish and line grade, as over the past 10 seasons, the average line grade for the #1 RB was 10.6th overall, and the grand average for a top 5 back was 13.04, bordering on that “above-average” tier.

So, how can this information be used? Well, taking a look at the consensus rankings for 2019, there are a handful of RBs who are highly ranked, yet are set to play behind a below-average line. Five top 11 backs, David Johnson (RB5), Melvin Gordon (RB7), Le’Veon Bell (RB6), Joe Mixon, (RB8) and Dalvin Cook (RB11), are all subject to what PFF believes to be bottom-eight units.  Volume will still likely trump this negative, but poor line play certainly gives way to a much lower floor when comparing these players to others who  will be running behind competent blockers. It’s not like these players are without question marks either. David Johnson is now in a completely new offense after coming off an awful season, Melvin Gordon may hold out and has injury concerns, Le’Veon Bell hasn’t played since 2017 and is on a brand new team, Joe Mixon doesn’t have the best QB at the helm and is going through a coaching change, and Dalvin Cook has missed more games (17) than he’s played (15). I’m not saying you should be passing on all of these players, but there’s certainly risk attached to each, especially when considering their blocking units will be far below par for the course.

Also, looking at where the #1 fantasy RB’s line ranked at the end of the season, there seems to be a correlation. 60% of the time, the number one back was behind a top-ten line, and just twice was the top producer playing behind a line that graded out as “below-average”. Yes, correlation does not imply causation, but these numbers should make fantasy players a bit less optimistic in believing a player like DJ, Mixon, or Cook have RB1 overall upside. Along with this, of the consensus “top four” (Zeke, CMC, Barkley, Kamara), Saquon is the only one of the bunch that is set to play behind a line that is ranked outside the top-ten (18th). This ranking still falls in the “average” range, so it isn’t a sign that you should completely fade him at the 1.01, but it certainly should be a factor in deciding who you will select if tasked with the conundrum.

Above, I put a different spin on things, looking at the top five offensive lines over the past 10 years and how their #1 back finished the season. In short, having a good line means you have a prettttyyyyyyy good chance at bordering RB1 status. There were a few instances where the No. 1 RB on a roster fell way down the end of season rankings despite playing behind an elite line, but as you can see in the “notes” column, most of the time, there was good reason for it. In 2011, for example, the Panthers had the 5th best run blocking unit, yet their RB1 failed to finish inside the top 20. Context certainloy matters, and in this situation, we can see that Carolina had a true RBBC where both Stewart and Williams had a near 50/50 split.

If we take out all of the fantasy finishes where I added notes (whenever a lead back fell outside the top-20), the average finish over the last 10 seasons would be RB9.90, or in layman’s terms, a top 10 back. Doing this may seem unfair, but keep in mind, on some occasions, RBs who finished inside the top 20 certainly could have had a better season, such as in 2017 for the Cowboys where Zeke played just 10 games, yet finished as the RB10. 

In the most basic sense, what this boils down to is, if a team has an elite offensive line, their starting back will likely produce at a high level (so long as there isn’t a true RBBC approach in that offense). Sure, a lot of these teams had what we believe to be “elite” backs, but just last season we saw James Conner nearly end as a top five RB, despite playing just 13 games and commanding a starting role for the first time in his young career. Even Nick Chubb, in only 9 starts, ended as the RB16. So, with all this being said, who should we be targeting heading into 2019 based on offensive line play?

Well, looking at what PFF projects for 2019, their top five lines are the Eagles, Cowboys, Steelers, Titans, and Colts. We saw that even with an elite line, RBs in a timeshare still struggle to produce top-12 numbers, so I’m not necessarily targeting a Philly RB, especially since we aren’t sure how healthy Miles Sanders is at this point of the offseason. His ADP has been falling, though, currently sitting at RB35, 85th overall, so if he begins to creep near that century mark, or falls to the RB40 range, I’ll be all in since he has the profile of a three-down back. We all know about the Cowboys and Zeke, so there’s no point in going in depth. Elliott should be a top four pick in all formats, and his line all but secures a top five finish.  The Steelers have always used a one-back approach, but with news surfacing that Jaylen Samuels will get more run than a typical #2 in Pittsburgh, I’m not yet all in on Conner. If during the preseason we see JC dominate touches (likely in week three), then my mind may be changed and he will probably make his way into my top ten. No promises, but we chase volume, and if their trend of feeding one RB continues, it’ll be hard to deny, especially behind that line, that he will return value. As for Tennessee, I’m not a Henry fan – at all – but if what we saw at the end of 2018 is the new norm, he has as good a chance as any to lead the league in rushing yards. Sure, he won’t catch 50 balls, but neither did Leonard Fournette during his rookie season and was still viewed as a top-eight RB. Again, this is a situation to monitor in the coming weeks, so if Henry gets a majority of the 1st/2nd down touches in the preseason, there is certainly reason to believe he has top-10 potential, as do most runningbacks with as good of an o-line as Tennessee. Lastly, Marlon Mack. The Colts’ line was incredible last year and it directly translated into production for MM, as he ended the year as the RB21 in just 12 games. If healthy for a full 16, he is almost guaranteed to flirt with a top ten finish, and considering you can grab him as the RB14, pick 27 overall, he is being taken near his floor.

Just looking at where the starting RB behind the league’s best blocking unit ranked, we can see there is a pretty good indication of being successful, outside of 2017. PFF’s grades heading into 2019 are not an exact science, more of a (very) educated guess, so just because Philly is #1 as of now doesn’t mean Miles Sanders or Jordan Howard is a lock for a ton-ten finish (especially since we don’t know how touches will be divvied up). What we can do, though, is look at units ranked inside the top-ten, pinpoint the projected lead back, and then use this data to support our views on potential breakouts.

The Colts, for example, are inside the top-five, and with Marlon Mack showing true workhorse ability, there’s certainly reason to believe he can continue the trend of returning value due to offensive line play. Hell, even Sony Michel, who, barring injury, will be the Patriots’ #1 back, is running behind PFF’s #6 line. He won’t catch a ton of passes, sure, but he was on pace for a 257/1,146/7 rushing line and averaged 112 rushing yards per game in the playoffs. He has fallen all the way down to RB26, pick 54 overall, and at that point, there really is little risk in grabbing him. If he stays healthy (which is a big if), I don’t see how he could fall outside the top-15 in all but a full-point-PPR setting.  He did have two years at Georgia where he topped 20 receptions, so maybe he will be a bit more involved through the air this season, bringing just a little more value, but even if he doesn’t, Michel is someone who could seriously flirt with 1,200 rushing yards and double digit scores, a ceiling that is nearly unattainable for any other back selected in his vicinity.

5 thoughts on “How Offensive Lines Impact Fantasy RB Production”

  1. myronbrowner5@gmail.com

    excellent take on o line and rb production. What about RB strength of schedules? Does it correlate to good production the following year? Im thinking about taking CMC 1st because he has the easiest SOS vs teams against the run compared to Zeke Barkley and Kamara.

  2. elunderskov@gmail.com

    So this is where I am struggling and changing my draft strategy at least daily; I have both Nuk and DJ on my team from last year in a keeper league, get to hold onto one but give up my 1st round pick. Who do you take in PPR? I’ve had DJ the last 3 seasons, and Nuk 2/3 years. Heartbreak is real.

  3. Mitchell Sanregret

    Great work! Love how you always go the extra mile with these analysis topics. One additional insight I’d be curious about is how often the PFF projected top 5 lines ends up actually performing as a top 5 line.

  4. On Henry…..”he has as good a chance as any to lead the league in rushing yards”…………….my man

    1st year with BDGE ….lost in the 1st round (previous 4 seasons made the semis; zero ships). But I have to say, I’ve never been more comfortable with my squad than in 2019. As I’m reading what you hit on in 2019….already excited about 2020.

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