This weekend I had a friendly conversation on twitter about whether or not size matters for wide receivers. It was pointed out that many of the best all time WRs, as well as several of the best in any given year, are not particularly tall or big. I thought I’d take a quick look at the numbers in a slightly different way than we usually do.
For some background, we’ve been talking about this issue a lot at House RotoViz as well. In one of the offseason’s seminal pieces, that sparked our frenzy of age-related material, Shawn Siegele noted that height didn’t appear to be a significant issue for WRs, but weight did. In response to many twitter draftniks who discount both height and weight, Davis Mattek later reminded us that size and scoring go together. But obviously guys like Steve Smith and Wes Welker have great success, as do plenty of guys who wouldn’t really be considered big, like Reggie Wayne and Marvin Harrison. Also, the Douche reminded us about the challenge of using cutoffs and non-continuous variables. So what gives?
All Time Greats
The first thing that occurred to me was to control a bit for era. To do this, I started with the top 311 WRs since 1970, by receiving yards and receptions. I intentionally excluded TDs. I didn’t want to penalize smaller receivers who historically don’t do as well in the red zone. I also figured that piling up yardage would be something that, theoretically, a smaller/quicker receiver could be as good, or better at, then a bigger receiver. Then I compared the height, weight, and BMI of each receiver to the average for all WRs drafted in the same year. I figured this would give me a sense of how these dominant WRs compared to both their peers and their defenders. Let’s take a look at how these all time great WRs compare to their draft year counterparts.
|Player||Draft Yr||Ht||Wt||BMI||Ave WR Ht||Ave WR Wt||Ave WR BMI||Ht Diff||Wt Diff||BMI Diff|
I used “1900” as the year for the averages row, just to make the table sort properly. Spend some time with that table, particularly the “difference” columns that show how the all-time great compared physically to other WRs from his draft class. Compared to other WRs:
- 20 of 31 all-time WRs were taller than the average WR
- 24 of 31 all-time WRs were heavier than the average WR
- 21 of 31 all-time WRs had a larger BMI than the average WR
- As a group, the all time WRs average height, weight, and BMI are larger than the overall WR cohort.
These findings are intriguing and support the notion that size matters for WR success, but this is a pretty small cohort. Still, it seems reasonable to say that size is an important factor in WR success.
Year Over Year
This time I took the top 10 receivers by year (based on receiving yards) and plotted their height, weight, and BMI.
Top 10 WR by Year
|year||Ave Ht||Ave Wt||Ave BMI|
Here are some charts that break that table down visually. First up, the average height of the top ten WRs by year, since 1970.
That’s a really interesting chart. It definitely looks like there have been some trends over time regarding height, but overall, the relationship between draft year and height is very weak, as evidenced by the low r^2.
Again, the NFL seems to have been exposed to some sort of shrink ray in the 1980s. But with weight, we definitely see a relationship over time; the top receivers are getting bigger.
The trend here is pretty unmistakeable. The best receivers, at least, are literally getting more massive as time goes on. That doesn’t always mean they’re taller, but they are getting heavier, particularly as their weight relates to their height.
For what it’s worth, the top ten WRs in any given year also outpace the size of WRs drafted that year, on average.
|Year||Top 10 Ht||Ave Ht||Top 10 Wt||Ave Wt||Top 10 BMI||Ave BMI||Ht Diff||Wt Diff||BMI Diff|
A few quick charts to show the draft trends at the WR position.
This looks a lot like the previous charts for height. Definitely trends over time, but overall not much of any correlation to draft year.
That’s a definite trend. NFL teams certainly seem to be increasingly valuing weight.
And, that’s pretty irrefutable. WR mass is clearly something valued by the NFL. If we assume that NFL teams draft players with physical profiles they expect to be successful, then it looks like we can assume the NFL thinks more massive WRs have a better chance of being successful.
Other Interesting Stuff
I also compared WR to data to defensive back data. Take a look.
I found these three charts quite interesting. There are challenges to using height as a variable, but it seems pretty clear that there’s a trend towards receivers getting taller while defensive backs are staying about the same height. It’s also interesting that, starting in about 2003, WRs have finally started outweighing defensive backs, on average, though they still trail in BMI. A few thoughts. It makes sense that defensive backs would have weight and mass on their side; they’re expected to tackle after all. WR and DB weight and BMI appear to trend pretty much in lock step. That could just be because all players are getting bigger as time goes on (although that wasn’t the case in the 1980s), or it could be because the best way to win against heavier DBs is to have heavier WRs. There’s not enough data here to make any conclusions about the relationship of WR size to DB size, but I think that relationship is also probably significant.
While this is not a definitive study, I think it does illustrate that size is an important consideration at the WR position. NFL teams appear to be increasingly valuing weight and mass, and as defensive backs also increase in weight and mass, it may be important for WRs to keep up. Since 1970, the best WRs on both an annual and all time basis have generally been larger than the average WR. This doesn’t mean that smaller WRs can’t succeed. But the trends support larger WRs having a better shot at dominance.
- I chose 31 because that gets Wes Welker in the cohort (back)