For years the ASA had three classes. A, B and C. A tasks were designed for SSA contests practice and followed those rules. B was around 70% of A tasking and C kept new to contest flying pilots within glide of the home airport while getting them used to contest rules.

When you won or came close to winning B class for the year you were moved up to A the next and those at the bottom. Of A were given the choice to go down to B. C class was hardly used but did come in handy at times.