# Relative Age Effect Analysis in the History of the Ballon d’Or (1956–2023)

## TL;DR

This study is the first to analyze the relative age effect in Ballon d’Or winners from 1956 to 2023, finding patterns in birthdates over time.

## Contribution

The study pioneers the analysis of relative age effect in Ballon d’Or history, revealing temporal shifts in birthdate patterns.

## Key findings

- A global relative age effect was detected in Ballon d’Or nominees.
- Early decades showed overrepresentation of late-year births, while recent decades show early-year overrepresentation.
- The relative age effect has resurged in recent years with more players born in the first quarter of the year.

## Abstract

Ballon d’Or is the most important individual award in football, and is a significant measure of excellence. From our knowledge, this is the first study that explored the relative age effect (RAE) throughout the history of the Ballon d’Or. A total of 1899 football players nominated for the award from the first edition in 1956 to the most recent edition (2023) were analyzed. To assess the RAE, the birthdate distributions were categorized into four trimesters. The comparison involved correcting for the uniform distribution using chi-square analysis, with Cramer’s V serving as a measure of effect size. Standardized residuals were computed to identify quarters that exhibited significant deviation from the expected values. Odds Ratio and 95% confidence intervals were used to identify discrepancies between trimesters. The results indicated a pronounced presence of an RAE at the global level. However, the longitudinal analysis revealed variations in the behavior of the RAE over time. In the initial decades, there is an overrepresentation of players born in the last months of the year. Subsequently, there is no discernible RAE. In the most recent decades, there has been a clear resurgence of RAE, with an overrepresentation of players born in the first quarters of the year.