In hockey, the players are much older in college, yet hockey uses birth year at the youth level. So these two concepts can mix very well. In hockey, if a kid goes to school "on age" (meaning they graduate HS in the same year that they turn 18 - but this will vary state to state), and is a college hockey prospect, it is often true that they are not yet ready to take a spot on a college team, so they are told to go to a prep school, or play juniors. For kids that are holdbacks - usually because they are at prep high schools or were just held back when they were younger, then they are more likely to go straight to the college team after HS.

The bottom line is that there are a ton of holdbacks in hockey, and the colleges mostly want the 19-20 yo freshmen, but so what - - because youth hockey is always played on age. In other words, it is exactly the same in college hockey, yet they seem to manage just fine with a youth system based on age.

This is what lacrosse people don't seem to understand when the two sides of the holdback argument yell at each other. You can still have age based youth play along with a system/culture filled with holdbacks and a college system that wants the older players for the competitive advantage they bring. I have never been anti-holdback. I have never cared if a kid is a 16 yo HS freshman, or a 20 yo college freshman. It doesn't affect my kid. I only care that in youth sports, they all play on age.

Also, the argument that says "hey in HS your kid will play against older kids so it is fine for it to never be aged based no matter what age or level they are at" is, and always has been, wrong. At HS the kid and his family CHOOSE to play varsity as a freshman (if offered by the coach). If they believe its not appropriate for their talented, but young, kid to play varsity, then the kid won't. I have seen it both ways. If the varsity level is very competitive, and the kid, while excellent, is small and not very physically mature, the family will say no, or sometimes, the coach just won't offer it. But some freshman are big and very mature, and sometimes the varsity level is not that competitive, and the kid will play. The bottom line is a choice can be made - to play JV or Freshmen team. Compare this to travel lacrosse, where the younger, smaller kid has no choice but to play against the older, bigger kid. The younger kid can't play down because he can't play below his grade.