Will Wearing the Rainbow Jersey Hinder Your Chances of Becoming a World Champion Cyclist?

Synopsis: The ‘rainbow jersey’ is the shirt worn by the current cycling world champion. Over the years, its wearer have been marked by various tragedies, most saliently, a lack of wins. And, fans being fans, how else do they explain this phenomenon other than suggest that the jersey must be ‘cursed’? Thomas Perneger, a clinical epidemiologist at the University of Geneva, put the limits of the ‘curse’ to the scientific test. For the years 1965–2013, Perneger analyzed the number of wins the champion won in his first year; second year (year he wore the ‘rainbow jersey’), and the third year.

Conclusion: Perneger found that the current champion was significantly less successful during the follow-up to his championship winning year. However, this trend was best explained by ‘regression to the mean’, rather than the curse of the rainbow jersey. This phenomenon also occurs in medicine, for example, a patient who loses bone density the first year is likely to improve at follow-up. Try telling that to your friends next time your team falls dramatically from grace, ‘Guys, we’re just regressing to the mean.’