Last week, I evaluated the assertion that high skill-position draft picks are a reliable source of rookie playing time, and decided that for fantasy football purposes, it's a crutch argument. In other words: It sounds good and props up whatever point you want to make, but it isn't necessarily true.
Today, I've got a related rookie claim to evaluate: "They invested in their offensive line in this year's draft; that's great news for the team's position players!"
Obviously, nobody is claiming that just because an NFL franchise selects one or more blockers early in a draft, their offense will explode in the subsequent season. That would be too rigorous a standard. But is there any kind of correlation? Does the influx of one or more highly drafted linemen tend to make a bottom-line position-player impact right away?
To me, this sounds like something people rattle off in an effort to provide overwhelming "evidence" for their opinion. You know: They're in the process of haranguing you about how Mark Ingram should be a first-round fantasy pick in 2015 (a defensible position!), and squeezed in among rhapsodic descriptions of Sean Payton's offensive genius and Ingram's 4.3 yards-per-carry average they say, "Plus they took Andrus Peat in the first round." But in evaluating this potential crutch argument, I tried to forget my bias, and approach this research project with an open mind.
There are probably several ways to evaluate whether the presence of blue-chip rookie linemen is good news for skill players. When establishing my method, I asked myself, "Aren't there different types of 'significant' investments a team can make in its offensive line?" After all, one franchise might select a tackle in the overall top 10, and another might use their second- and third-rounders on a pair of guards. Also, what are good metrics to ascertain whether an offensive situation has "improved"? Here's how I decided to proceed:
I used the standard NFL Draft Value Chart, in which draft picks are assigned a numerical value that descends from 3,000 for the first overall pick, down to 590 for the final pick of the first round, down to 270 for the final pick in the second, 116 for the final pick in the third, and so on. That way, I could add multiple O-line picks from the same season to get a rough idea of their combined value.
By way of assessing an offensive line draft class's effectiveness, I chose to examine teams' year-over-year yardage changes (with rushing yards and passing yards assessed separately) and fantasy point changes for the quarterbacks and running backs on the relevant teams.
Let's look at a few examples. In 2014, the St. Louis Rams selected tackle Greg Robinson with the second overall pick (worth 2,600 draft points on the Draft Value Chart) and tackle Mitchell Van Dyk with a seventh-rounder (worth one draft point), for a total of 2,601 points, which represented the highest investment of any franchise in the 2014 draft. The Atlanta Falcons made the second-highest investment by taking tackle Jake Matthews at No. 6 overall (1,600 points), the Tennessee Titans were third taking tackle Taylor Lewan at No. 11 overall (1,250 points), and the Miami Dolphins were fourth selecting tackles Ja'Wuan James No. 19 and Billy Turner No. 67 (1,130 combined points).
Here's how these teams fared offensively in 2014 compared to 2013:
Again, I'm not expecting every single test case to have resulted in improvement. This is a small sample size by way of introduction to my methodology. With a technique established, let's dig into the past five years' worth of data and see if we can find any trends.
Teams that made O-line investments of at least 270 draft points
Since the No. 64 overall pick is worth 270 draft points, that seems like a good cutoff to explore teams who've done at least the "equivalent" of second-round work on their blocking. It doesn't mean they actually used a second-round pick on an O-lineman; using multiple later-round picks can also meet the threshold for this level of investment.
Over the past five drafts, 58 teams have reached this investment level. Here's how their offenses have changed in the subsequent season:
Hey, that doesn't look so bad! These offenses haven't improved by huge amounts, but they have improved. A closer look, though, tells us that while the average improved, an awful lot of individual teams didn't:
I feel comfortable saying that these offenses tended to get a bit better rather than worse. But I don't think the evidence is overwhelming, and it obviously wasn't automatic. Using at least a second-round pick's worth of draft value on offensive linemen was no magic tonic for these offenses or the skill players therein.
Teams that made O-line investments of at least 590 draft points
Let's be even more stringent with our criteria. Let's only look at draft investments that were the equivalent of a first-round draft pick. Over the past five years, only 31 teams made such investments. Here's how their offenses changed the season after:
For this elite group, these average improvements are better in every category, lending credence to the idea that there might be some (perhaps minor) causality between how high linemen are selected, and how big their bottom-line rookie impacts are. But again, when we look team by team, there's nothing definitive:
Conclusions
The fact is, of course, that it's facile to ascribe an entire offense's year-over-year improvement or deterioration to an influx of one or more rookie O-linemen. Just look at the four specific teams from 2014 I already mentioned. Last season, the Rams got zero games from their starting quarterback, which was assuredly a larger factor in their total offensive performance than any new lineman. The Falcons couldn't keep veteran blockers like Sam Baker, Joe Hawley and Lamar Holmes healthy, and at one point had tight end Levine Toilolo playing left tackle. Recently the Titans have whiffed on multiple O-line veteran free agents (Andy Levitre and Michael Oher come to mind). And the Dolphins recovered from a scandal-plagued 2013 with better health and more harmony among their O-line veterans.
And that's the point! In retrospect, we can almost always point to a myriad reasons why an offensive line gelled or backslid, and a primary explanation is rarely "boy those rookie blockers really turned everything around." As indicators go, rookie linemen lag, they don't lead. Are there exceptions? Sure. I thought the Chicago Bears' 2013 draft that netted them guard Kyle Long and tackle Jordan Mills (876.2 draft points) made an obvious difference on tape, one that helped Matt Forte to a monster season. But identifying such relatively rare instances before the fact -- amid many cases where highly drafted linemen needed multiple seasons to become difference makers -- is a difficult task.
My argument here is not that NFL teams are dumb for selecting linemen. There does seem to be evidence that highly drafted rookie linemen tend to do more good than harm: Each team's story is different each season, but when compiling five years' of data into raw averages, we see that overall offensive output tends to improve, albeit slightly. Plus, the benefits of having good O-linemen on hand as they mature into their primes are obvious.
No, my point here is simply that if you're using the fact that an NFL team drafted blue-chip rookie linemen as justification for why you like a running back, quarterback or wide receiver for fantasy purposes, you're employing a crutch argument. There are several reasons to be interested in Mark Ingram this season. I'm simply guessing Andrus Peat isn't prime among them.