Regression to the mean explains that in many cases data will tend to even out—i.e., if a variable is extreme on the first observation, it will tend to be closer to the mean on the next observation.

Regression to the mean is driven by chance, and so it occurs wherever chance occurs, which means it occurs almost everywhere. It is prevalent in sport and can explain the “ manager of the month ...

An analysis that corrects for 'regression to the mean'. Eur J Epidemiol 2013; 28: 859–866. Article Google Scholar Iversen GR . Statistics: The Conceptual Approach. Springer, New York, NY, USA, 1997.