Size Does Matter: How an NFL Player's Height and Weight Affect Performance

re’s no relationship whatsoever (a scattered mess), it’s zero.

I took the career statistics of every player post-1980 (with 300 career pass attempts, 100 rush attempts, or 100 receptions) and plotted them with their height and weight. Here are the results.

 
In this scenario, a positive correlation means that taller or heavier players have better statistics than shorter, lighter players, aside from interceptions, which is the other way around.

We see a small positive correlation between weight and most passing stats (all those except yards per attempt). In each case, as weight increases, the stat in question rises accordingly (or drops, in the case of interceptions).

The largest correlation between height and any passing statistic is, interestingly, between height and completion percentage, though the correlation is negligible.

There’s not much correlation between measurables and rushing statistics, with the obvious exception of weight and rushing touchdowns. Heavier running backs tend to be the ones who score the most touchdowns, which is what we expected.

Then there’s the wideouts. There’s a very strong correlation between weight and yards per catch, at -0.653, which means that, somewhat counter-intuitively, shorter wide receivers have more yards per catch than taller receivers.

The correlation is even more staggering when you consider that there were fewer than 100 unique weights for the more than 400 receivers in the study; it rises to -0.819 when you only look at the average yards per catch at each of those unique weights.

This, in turn, brings up a good point: If there are so few unique weights or heights (of which there were 14 between those 400 receivers), then looking at correlation coefficients won’t show the real relationship between measurables and on-field production.

In other words, in order to look at this relationship (or non-relationship), we must group receivers based on their height and weight and look at the statistics from the totals in each bin of receivers. I did this for each position, making sure each bin had a sufficient number of players in it (at least 40 or so).

Here are the results for quarterbacks. All heights are in inches and all weights in pounds.

 
A quarterback’s performance tends to be highest when the passer is 74 inches tall (6'2"), but this could also be contributed to the fact that, either coincidentally or not, Brett Favre, Joe Montana, Steve Young, and Kurt Warner were all 74 inches.

Removing that particular height, quarterback rating increases at each height increment. As well, completion percentage for the shortest quarterbacks is lower than any other height, a full point lower than the tallest players’ completion percentage.

That said, there’s no real pattern between height and completion percentage beyond that.

The largest correlation comes from weight and interception percentage. Interceptions decreased each time weight increased, with a steep decline from quarterbacks weighing over 215 pounds.

I’m hypothesizing here, so bear with me, but heavier quarterbacks may be more inclined to take a sack under pressure, whereas lighter ones will instead throw the ball up to evade a sack.

I don’t have sack data, so I can’t test this hypothesis. This may be, however, just a correlation/causation issue—in other words, there may be another outside factor affecting interceptions.

In addition to looking at the average statistics at each height or weight, I also looked at the chance of a "great" season by looking at the odds of finishing in the top quarter in that particular stat.

I only included seasons where the quarterback had 350 pass attempts. Here are the results.

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