Debunking the curse of the rainbow jersey: historical cohort study.

OBJECTIVE

To understand the underlying mechanism of the "curse of the rainbow jersey," the lack of wins that purportedly affects the current cycling world champion.

DESIGN

Historical cohort study.

SETTING

On the road.

PARTICIPANTS

Professional cyclists who won the World Championship Road Race or the Tour of Lombardy, 1965-2013.

MAIN OUTCOME MEASURES: Number of professional wins per season in the year when the target race was won (year 0) and in the two following years (years 1 and 2; the world champion wears the rainbow jersey in year 1). The following hypotheses were tested: the "spotlight effect" (that is, people notice when a champion loses), the "marked man hypothesis" (the champion, who must wear a visible jersey, is marked closely by competitors), and "regression to the mean" (a successful season will be generally followed by a less successful one).

RESULTS

On average, world champions registered 5.04 wins in year 0, 3.96 in year 1, and 3.47 in year 2; meanwhile, winners of the Tour of Lombardy registered 5.08, 4.22, and 3.83 wins. In a regression model that accounted for the propensity to win of each rider, the baseline year accrued more wins than did the other years (win ratio 1.49, 95% confidence interval 1.24 to 1.80), but the year in the rainbow jersey did not differ significantly from other cycling seasons.

CONCLUSIONS

The cycling world champion is significantly less successful during the year when he wears the rainbow jersey than in the previous year, but this is best explained by regression to the mean, not by a curse.