Not sure how it is in Maryland but in Virginia at the 10U, 12U and 14U level but most rec teams have A and B teams and almost assuredly most A teams are comprised of the upper age group with a sprinkling in of younger players that can play with those kids - in other words younger players play up - as it was for almost the beginning of the creation of youth sports. If you were good, you played up. Holdbacks are essentially playing down. That is the issue. | 
