If you're new to competitive soccer, the readers digest version of how competitive soccer works is as follows: US Soccer (the national governing body of youth soccer) sorts competitive players into teams based on their birth year. So when you see "birth year", that means that your son/daughter will tryout and play with kids all born in that same year. So when we field a 2010 girls team, it's all girls born in 2010. Kids are technically allowed to roster with an older team (a 2010 birth year player can play "up" into a 2009 team) if approved by parent and SSFC coaches/administration. However, players can't play "down" into a younger age group at any time.