Equitable birthdate categorization systems for organized minor sports competition

In some organized minor sports programs where there is early competitive streaming, players born early in the year are more likely to reach elite levels than those born late in the year. This is generally attributed to the calendar year system most minor sports programs use to group players for the purposes of competition. In this paper I show how to devise more equitable systems based only on player ages. These systems rotate the relative age advantage so that those players born late in the calendar year are not always the youngest players in their age division.