I went through this last year with JV games. When the AD's called with dates I just explained that my varsity and college schedule was taking more and more of time time so I needed to cut back on the lower level dates. I always thanked them for thinking of me and told them that if they get in a real bind and need someone on short notice, I'd be happy to help out on occasion. I'm hoping to have the same conversation with some AD's about Varsity games in the next few years.