An ex-footballer was telling me how one of the biggest challenges he sees in the younger generation of players is their lack of resilience. He feels we are raising an entire generation of youth who do not know how to fail because they have never been allowed to.
Puberty affects boys and girls differently. Boys especially often grow through an awkward, ungainly stage where they no longer seem to be as coordinated. Girls often develop more quickly than boys, both mentally and physically. This is a large part of the reason why girls often commit to college teams before boys.