BMI Matters for Wide Receiver Prospects

One of the hotter recent topics on twitter and elsewhere has been the function Body-Mass Index (BMI) serves in projecting wide receiver success in the NFL. It came up in my recent post requesting questions for the DLF Mailbag. The issue deserves enough additional exploration to warrant an independent article. So let’s dig in!

NFL Combine weigh-ins are tracked closely and are an important consideration in rookie evaluations. Prospect height and weight are scrutinized because historical data suggests there are thresholds for success at various positions. BMI may be a relevant metric to factor into prospects for dynasty purposes. It has not been considered much for wide receivers. This article will focus on the relationship of BMI with fantasy outcomes, and not with NFL success or performance directly.

For reference, BMI is a person’s weight (in kilograms) divided by the square of their height (in meters). Essentially, this boils down to factoring in both height and weight to have a comparison point between people. Just think about how two people can have similar weight, but if they are a foot apart in height, their body composition will be substantially different.

Draft capital and BMI

One consideration is whether BMI is something relevant for how NFL teams prioritize and select wide receivers. I am not suggesting that teams explicitly draft players with certain BMIs, but rather that other factors they favor may correlate with BMI. This makes it a noteworthy consideration for our pre-draft prospect evaluation since it correlates with draft capital, a metric that is associated with opportunity and fantasy relevance. So how does BMI relate to draft capital?

Above is a list of all the first round wide receivers drafted since 2010 organized by descending BMI. The first round is somewhat weighted toward higher BMIs. For example, as shown below, 52.3% of all receivers drafted in this time frame are above a BMI of 27, whereas 67.6% of them selected in the first round exceed this figure. Similarly, 75.9% were above 26 and 85.2% of first rounders exceeded that threshold.

The chart shows that BMI shifts dramatically during the course of the NFL draft. This indicates NFL teams are favoring players with higher BMIs more heavily in the earlier rounds. Again, I am not suggesting BMI is the reason they are being drafted, just that it correlates (relates to) with other factors/metrics that NFL teams prioritize.

BMI and historical success – a capped ceiling

If we are to consider a potential cutoff for BMI, 26 seems to have some interesting fantasy significance. Since 2000, only two wide receivers with a BMI under 26 have scored over 20 points per game or more in a season (Randy Moss and Marvin Harrison). For wide receivers over a BMI of 26, the group widens by a huge margin (see below for a portion of the list).

When we are evaluating rookie prospects, we tend to have rose-colored glasses envisioning the upside and massive ceiling they may offer us. This BMI finding is worth considering since it does suggest that players below the 26 BMI are highly unlikely to offer the elite upside we seek.

Wide Receiver Tier Performance and BMI

Elite performance is great, but a steady contributor on our squad still provides value and can win leagues. Let’s anecdotally take a look at how BMI relates to performing in various tiers (WR1, WR2, WR3) since 2010.

The average points scored to achieve a top-12 wide receiver season the past three years was 16.1 PPR points per game. Here is the list of players to achieve that status with a BMI of less than 26:

This has only been achieved nine times in the past ten years – with five of them being accounted for by one player (AJ Green) – and further supports the notion that the ceiling is limited for any player entering the league with a BMI under this 26 threshold.

If we expand the search to include players under a BMI of 27 (i.e., between 26 and 27), the number of top-12 wide receiver seasons is much greater. This adds in players such as Antonio Brown, Tyreek Hill, Michael Thomas, Eric Decker, TY Hilton, and Brandin Cooks, all players who have found consistent success as steady top-12 options this decade.

What about top 24 and 36 Wide Receiver?

We do not always need top-12 wide receivers for our rosters. Second and third wide receivers can be the backbone of lineups and be a successful rookie selection. The average score for a replaceable top-24 wide receiver during the past three seasons was 13.6 PPR points per game. Using this as a cutoff, 17 players with a BMI of less than 26 scored as a WR2 during the past ten seasons. This accounts for 14.1% of WR2 performances, which is meaningful because 24.1% of wide receivers drafted have a BMI below 26. The ratio of players at this BMI in the league remains much higher than their ability to perform at the level of a top 24 option for fantasy.

What about wide receivers finishing between 25-36 (11.7 PPGs)? Nineteen players (15.8%) with a sub-26 BMI achieved a WR3 season since 2010. Again, this is below what we would predict based on the ratio of players with this BMI.

Conclusions

The main takeaway is that there appears to be a meaningful relationship between BMI and projecting future fantasy outcomes. It is highly unlikely that a player with a BMI less than 26 is going to enter the elite stratosphere of fantasy receiver. A low BMI player will generally have a capped ceiling for their performances.

There also seems to be a reduced likelihood that these players will perform as top-24 and top-36 options. But an important caveat is that many sub-26 BMI players are drafted later in the NFL draft, which speaks to a lower quality of player (in theory). Thus they are less likely to achieve a top-36 performance because they are not as skilled, less likely to have an opportunity, and may not even be on a roster.

So what do we do with this information?

There is enough anecdotal evidence from this examination to include BMI as a worthwhile consideration for rookie prospects. My initial reaction, though, is that this should be reserved for top prospects who are projected as early first round rookie selections. These are players that we hope will enter into an elite tier and offer perennial league winning production. If we can fade a player below a BMI of 26, it may be best to do so because history shows us they are just not going to perform at that level.

For players beyond the top of the draft, there is not enough evidence that you should fade a wide receiver because of BMI. If they have draft capital and other metrics of NFL success, there is still a likelihood they can be a steady fantasy contributor and there is no reason to rule them out because of this particular metric.

Lastly, what is the “optimal BMI”? I would place it between 27.5 and 28. Since 2000, this includes players such as Julio Jones, Hines Ward, DeAndre Hopkins, Terrell Owens, Odell Beckham Jr, Brandon Marshall, and Calvin Johnson (among others). This is truly the prototypical size and weight of an elite prospect who can dominate at the next level. It seems to be a “sweet spot” that has projected some amazing success at the next level.

Data courtesy of Pro-Football-Reference.com. I want to acknowledge @ff_Sleepy for identifying the 26 BMI threshold in a recent tweet.

Thank you for reading. You can follow me @FF_TomB. I am always happy to answer questions and chat all things fantasy.