I was watching videos of past U.S. Amateur winners and was wonder is there some sort of unspoken age limit on this event? On the USGA site it says their is no age limit, but nearly all of the past fields are comprised of late teen/early 20 year olds. I'm know there are competitive 30/40/50 year olds, yet the field remains skewed to the younger demographic. What is the cause of this?