Correlation, Causation, and the NFL

It’s Football Season…

Tom Brady posted about the Madden “curse” the other day and it got me thinking, “Is it really a curse or just clever manipulation of events?” Of course, this reminded me of how often people confuse correlation with causation. My initial example (on my Instagram account) was about vaccines and autism (that’s a link to the retraction), but it drew too much heat. So, let’s try this again with football and the NFL.

What is the Curse

There are currently 21 Madden covers (1999-2019) and 24 players that have graced the covers. But before I begin my statistical analysis, let us first define the curse.

The Madden curse is the superstition that a player will be injured or experience a decline in performance in the season he appears on the cover.

Rule Changes

Seventeen players out of 24 were considered “cursed”, which is a whopping 71%! But if you dig a bit deeper, you’ll see that there were only 8 injuries out of the 17 cursed players. The rest either lost their mojo (we’ll get to this later) or entered the season with lingering injuries.

The last “cursed” player was Troy Polamalu; he suffered an injury during the 2010 season. Fun fact, the NFL began dealing with CTE and concussion issues around that same time. Gooddell had to stand in front of Congress (in 2009) and explain why the NFL wasn’t doing much despite all the CTE research. Fast forward to today and you’ll notice that the rules about tackling and hitting are much stricter. Could this be the reason for the drop in injuries? Answer is yes.
If you look at the data in the last 6 years, 0% of healthy Madden players suffered injuries. People may try to argue and say, “Wait, what about Adrian Peterson and Rob Gronkowski!” Those guys both entered the season already injured, so the likelihood of a performance decline or re-injuring seems pretty high, no?

Mojo Loss

Ok, let’s talk about the lost mojo. Out of 19 cursed players, 8 lost their mojo. Two of the 8 (see above statement about Peterson and Gronkowski) came into the season with lingering health issues. So there’s a good reason for the overall decline in performance: the fragility of the human body. Or age and time.

Football is a violent game. The longer you stay, the more beat up you get. But the longer you play and the better you are, the more famous you become! The average years between the Madden cover (fame) and retirement (age & time catching up) is 3.6 years. The two outliers are Drew Brees (who is still playing) and Ray Lewis (who retired 7 years after his Madden cover). Take them out and the average goes down to 2.3 years. Makes sense right? Madden covers celebrate the best of the best, well-known veteran players who either just won a Superbowl or broke some insane record. Once they’ve got their ring, it makes sense to bow out and enjoy life.

Correlation and Causation

While it may seem like the Madden cover is causing people’s career to crumble, it’s not. The “curse” happens because Madden only picks accomplished players. The correlation or relationship between the covers and the decline in performance is age and time. Age and time are the two things causing players’ performances to decline. I like to tweak the old expression about hitting rock bottom and say that, once you’re at the top, the only place to go is down. Unless, of course, you’re Tom Brady.

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