From 1965-2000, USA Swimming recognized the fastest 16 swimmers in each age group. In 2000, rather than honor the top 16 in each age group, we chose to recognize the top 10 swimmers per age.
The All-Time Top 100 is a ranking of the fastest times by age group, event, course and gender throughout competitive swimming. The All Time Top 100 ranking is a listing of times derived from the Top 16 and Top 10 list each year. Therefore, in order to be on the Top 100 ranking, you must be on the Top 16 or Top 10 list. You can qualify for the All-Time Top 100 list in any and all of the events recognized in your age group by USA Swimming.