And behold, the bimodal pattern that my students kept seeing. And if you didn’t know anything about football, you’d immediately ask, “Where are the people between 230-280lbs?And why is there such a peak of people around 300lbs? I combed through and assigned general categories to all of the positions, and really the only position that approximated a normal, average-sized American male (~194 lbs) are the defensive backs and receivers.However, something caught me a little off guard – I expected the distribution of players to be normally distributed, but perhaps with the means substantially higher than the distribution of males in the United States.In fact, the last question of my lab was “does the distribution of weights for your team look normal?Also, where are all of the players between 250-280lbs? Well, for the receiver distribution, it’s under-represented on the right side, and the same for tight ends (although there’s some outliers around 300lbs – I’ll come back to this). Several years ago, OK Cupid, an online dating website, published a bunch of blog entries on their website based on the data from their users.Meanwhile, the offensive line looks at first blush to be normally distributed, but failed the empirical rule by being over-represented around the mean (300lbs). When they simply plotted out the self-reported heights of their users, they noticed a weird trend with the male users.” However, for even the casual observer of football, you’d immediately say, “Well, the big peak is the ‘skill players’ and the smaller peak is the ‘linemen’ who are for the most part really big dudes.” What happens when you split it up by offense and defense, and the bi-modal distribution is clearly there on offense, but not really on defense. I then put them through the Shapiro-Wilk Test for Normality, and all but three were “normal.” The three? Receiver – Not Normal Runningback – Normal Quaterback – Normal Tight End – Not Normal Offensive Line – Not Normal Defensive Back – Normal Linebacker – Normal Defensive Line – Normal Now on the defensive side of the ball, it looks like there’s some decent overlap between all three categories, although there’s some serious lumping going here by combining defensive ends and defensive tackles, inside and outside linebackers, and corners and safeties.
Well, I think we know what’s going on here – almost every guy on a dating site adds an inch or two to their height, and that 6 foot is perceived to be a benchmark height that guys think women want.
Now imagine an athletic, but big kid comes in at 260lbs to play tight end, and he also goes through a growth spurt in his first year.