The National Motor Freight Traffic Association (NMFTA) annually publishes a list of freight class designations, codes, and subclasses for commonly shipped items (https://classit.nmfta.org/). To access this list, you are required to pay a subscription fee. Learn more about freight classes for free on our freight classes pages.
Freight class 50 is the least expensive because it refers to the freight that is easiest to transport for the carriers.
The NMFC freight class for baseballs is 85.