Competitive Balance in the NFL

With the NFL regular season over, let's take a look at how competitively balanced the NFL was since 1981.  As a reminder, I am using the Noll-Scully measure of competitive balance which statistically measures the actual performance from the ideal performance.  An ideal level of competitive balance using the Noll-Scully measure would equal 1.000, and levels above 1.000 means that the league has some competitive imbalance, with higher Noll-Scully numbers meaning more competitive imbalance.  (Here is a step-by-step guide if you want to calculate this on your own.)  By competitive balance I am looking at how well a league's standings are in relation to a league where wins and losses are determined randomly.  In order to do this, I am going to look at the NFL season statistically as a sample and as a population - mainly for comparison purposes.  The data comes from profootball-reference.com. 

As you can see below, whether I use a sample or the population, the Noll-Scully measure of competitive balance is very similar.  Additionally, the level of competitive balance has not changed much over the last few seasons, with the Noll-Scully for a sample in 2017 equal to 1.601 and for the population equal to 1.576.  So even with the Brown's win-less season, competitive balance has not declined much from last season.