Fantasy Football: Forecasting Offensive Lines & Drafting
Unless you decided to formulate a fantasy league starting 5 O-Linemen and a long snapper, you likely aren’t paying attention to the “who’s who” of the men in the trenches apart from your favorite team or a Pro-Bowl list. Offensive lines don’t generate fantasy points themselves although this collective group occupies at least 45% of the offensive side of the ball on every single play.
How much weight should these heavy-set men play into how we draft in fantasy football? Projecting and rating offensive line play isn’t a precise analysis nor a scientific method. However, there are some systems and evaluation tools that can add a tasty piece to the pie. Adding a hefty portion of OL mincemeat pie to our plate gives us a more well-rounded meal. However, as we’ll come to see, OL projections, especially in the preseason, should be thoroughly vetted when evaluating fantasy commodities.
What Do We Actually Know?
As many have attested, offensive line play is not an exact science but it is also not so mysterious that we live in the dark. The offensive line is 5 men acting as one while also coming to terms with the simple fact that weak links in the line make an easy point of exploitation for opposing defenses. Because the ball is not in their hands, it can be difficult to gather meaningful data. They often can be injured and become interchangeable play to play without many of us even noticing a difference. Here are some of the major sites and offensive metrics used to grade out how we can measure an offensive line’s value and effectiveness.
Football Outsiders– FO is the preeminent voice of DVOA rankings used by many and gives us an even more distinct take on OLine rankings. For run blocking, the Adjusted Line Yards formula takes all running back carries and assigns responsibility to the offensive line. For pass blocking, teams are ranked according to Adjusted Sack Rate, which gives sacks (plus intentional grounding penalties) per pass attempt adjusted for down, distance, and opponent.
Pro Football Focus– You probably know this by now, but PFF is the standard in this industry of taking a play-by-play approach to grading players. For offensive lines, PFF OL unit grades are based on a number of signature stats (hurries, hits, sacks, and total pressures allowed) encapsulated in their PBE rating (pass-blocking efficiency) as well as individual run-blocking grades.
NFL Next Gen Stats– Our fellow Reception Perception colleague Matt Harmon recently helped give some credence to NFL’s Next Gen Stats highlighting pressures allowed for its main pass blocking metric and yards gained before close (YGBC) for run blocking. YGBC measures the “amount of rushing yards a RB gains before opposing defenders come within 1 yard of the player”. To give some context, the league average in 2017 was 0.29 YGBC, with the Saints leading with an insane 0.87.

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Other OL stats: A plethora of other great sites base their offensive line rankings on raw numbers of the following, which can be misleading if taken as the only piece of the offensive line puzzle:
- Experience: shows the number of games played by a lineman but not necessarily as a collective unit
- Negative runs: the percentage of rushes that lose yardage often indicates when an OL has been blown up by a defensive tackle or a blitzing linebacker. However, this can also be an extremely skewed number when you have an RB with poor vision such as Alfred Blue, who knows only how to plow straight into a pile
- Yards per carry: Woof. There’s a lack of “stickiness” that yards per carry has in evaluating year-to-year fantasy value. In mathematical terms, the small sample size allows for ypc numbers to fluctuate at inordinate levels and therefore be subject to volatility. Chase Stuart from FootballPerspective.com recently conveyed this precedent in a case study. As you’ll see below, this stat is dependent on volume and outlier runs to boost a line’s potential.
- QB Hits/Sacks: gives a limited picture without accounting for events the QB scrambled into or the failed blocking assignments blown by RBs, etc.
OLine Analysis: A Mixed Bag
As I perused across a number of sites, here a few teams that impacted fantasy lineups greatly in 2017 with some mixed-up results.
Run Blocking Ranks | Pass Blocking Ranks | |||||
---|---|---|---|---|---|---|
Team | PFF | FO | Next Gen | PFF | FO | Next Gen |
Philadelphia Eagles | 4th | 22nd | >20 | 12th | 12th | >20 |
New Orleans Saints | 18th | 2nd | 1st | 3rd | 2nd | 1st |
Buffalo Bills | 14th | 27th | 2nd | 2nd | 31st | 7th |
New England Patriots | 1st | 1st | * | 8th | 14th | * |
Dallas Cowboys | 2nd | 4th | 20th | 18th | 15th | * |
Los Angeles Rams | 3rd | 3rd | 3rd | 14th | 9th | 8th |
*Next Gen Data ranks for these teams not available.
- The Eagles are a giant conundrum ranked as PFF’s #1 overall line and FO’s 22nd ranked run blocking, while Next Gen was a bit more skeptical ranking them outside the top 20 on both of their major metrics. In terms of pressure, the unit gave up 129 pressures from the left side of their offensive line, the third-most among any team in 2017. Much of their success could be attributed to Doug Pederson‘s scheming and taking advantage of run-pass options.
- New Orleans is an interesting case study as PFF had New Orleans as the 18th in run blocking while Next Gen had them first and FO 2nd overall. FO rated the Saints #1 in 2016 as well. Their success in 2016 dictated that the offense transitioning from a Drew Brees-led 5,000 yard type of season to a more run-oriented system was foreseeable. In other words, you could’ve placed your chips on someone from the Saints backfield at the beginning of 2017 (Adrian Peterson, Mark Ingram, and Alvin Kamara) becoming a big beneficiary
- Football Outsiders had Buffalo as the 2nd worst pass-blocking unit while PFF had them as the 2nd highest pass-blocking efficiency rating. So what gives? The PFF pass-blocking number isolates the O-Line play from the QB, where Tyrod Taylor was charged with a league-high 14 sacks. In other words, the number is skewed when Taylor’s scrambling ability in the pocket stresses the line.
- The Los Angeles Rams were a porous unit under their previous regime (ahem Jeff Fisher) ranking 29th in run and pass blocking respectively by Football Outsiders. After having a major upgrade signing OT Andrew Whitworth, they were still ranked 18th as a unit by PFF before the season. All the Rams and Sean McVay decided to do was give Todd Gurley 366 opportunities to showcase his abilities and finish as the 3rd overall run-blocking unit by all 3 major sites. Impressive.
- The Patriots also were a bit of a surprise… especially considering the revolving door at RB between Mike Gilislee, Dion Lewis, James White and Rex Burkhead. New England ranked 19th in the preseason by PFF but finished as run-blocking road pavers in every metric imaginable.
2017 Cleveland Browns: A Case Study
As with any set of data, the end of season numbers we see is mostly descriptive than predictive of what is to come for the following year. What fantasy owners and prognosticators are more interested in for 2018 is what can be championed during the offseason and trumpeted before league drafts. Let’s take a look at last season and an interesting case study of what offensive line hype looked like as many in the fantasy community banged the table for a certain Browns RB.

Nick Cammett/Diamond Images/Getty Images
Much of the hype surrounding Isaiah Crowell last year was due to FA acquisitions Kevin Zeitler and the often injured J.C. Tretter that many thought could help “leapfrog” other well-equipped lines. Cleveland’s offensive line was ranked No. 2 to start 2017 by PFF after ending 2016 as the 16th ranked unit. Here’s “What Went Wrong”, recently highlighted in depth in a separate article:
- The Browns infamously got worse falling to 0-16 on the season after it was assumed “things couldn’t get worse”. Part of the concern was that this unit had never actually played together before although they were “anointed” as OL saviors. Zeitler graded out as PFF’s 10th best guard and Tretter was a middle-of-the-road 16th center.
- The O-Line definitely improved but Joe Thomas‘ injury ending up exposing their lack of depth. According to Football Outsiders, the Browns ranked 14th in run blocking and 22nd in pass protection. With PFF, they ended the year as 19th best in pass blocking efficiency, a plummet from being the 2nd ranked unit going into the season.
- What was more indicative was the simple fact that Cleveland ran only 46 plays inside their opponents 10-yard line… or 13 less than the previous year. In other words, the supposed “increased” opportunities actually got worse for Crowell. He ended with only 2 rushing TDs.
- The Browns also allowed the 6th most sacks (50) and the most QB Hits (130), although much of this can be attributed to DeShone Kizer‘s frantic play.
In summary, if you weighed the offensive line forecast of the Browns heavily in your assessment of a player like Isaiah Crowell in 2017, you likely were left burned by an early round pick that eventually hit your waiver wires. Betting on an anemic offense and putrid team to even get incrementally better isn’t always a given even with a perceived offensive line upgrade. Drafting a player like Crowell (who had never been an RB1 nor considered a top talent) at an RB1 price was his best-case-scenario.
How Can We Forecast?
Taking these grades and rankings into our draft rooms will only give us yet another spreadsheet and set of data to synthesize towards making an actual selection. Here are PFF’s top 10 preseason and final rankings of 2016 and 2017:
Offensive line ratings were much more indicative about dominant rushing attacks than maybe we realize. One of the main factors that did show up in top-ranked units was continuity, having the same unit from one year to the next. Real chemistry and consistency are what made a blocking brigade. Using the Saints again as a great example, Football Outsiders’ formula gave New Orleans a league-leading 4.93 adjusted line yards in 2016. They repeated that exact mark in 2017 to finish slightly behind New England for 2nd place with roughly the same OLine group.
Pass protection was much more QB-dependent in PFF grades as the running QBs (think: Tyrod Taylor or Jacoby Brissett) often made mistakes or held onto the ball longer than they should have. Many are praised for their ability to “move around the pocket” despite not really being elusive threats. Tom Brady is a great example of this. QBs with a quick release (Drew Brees or Jimmy Garoppolo) also minimize their line’s pressures allowed as they have better instincts for the rush.
Conclusion: How Much Should We Weigh O-Lines?
In summation, it’s clear that offensive line grading must be taken in context especially when utilizing a plethora of different sites (PFF, FO and Next Gen) to validate your fantasy football decisions. The predictions from year-to-year are obviously not an exact science but nevertheless cannot be ignored. Injuries and poor QB play can hide the potential of an offensive line. However, the run-blocking performance of an OLine can be paired with a talented RB (ala Todd Gurley) to form an unbelievable duo for fantasy football purposes. As you get closer to draft time and preseason OLine rankings come out, take just a moment to compare the data and come to your own conclusions.