Several years ago, USA Swimming looked at 10 & Unders who were ranked in the Top 16 and followed the likelihood that they would still be ranked once they were in high school. This is what we found:
Ranked Top 16 as a:
10 & Under Still Ranked as 17-18 11%
11-12 Still Ranked as 17-18 21%
13-14 Still Ranked as 17-18 36%
15-16 Still Ranked as 17-18 48%
Moral of the Story: A 10 & Under can survive and thrive...but 50% of the top swimmers develop AFTER Junior Year in High School. If you have age-group athlete, make sure you emphasize fun, participation in a variety of sports and activities, including unstructured play and skill development and that there is a long-term progression plan. Discourage early specialization in one sport or one event.