According to this [bulbapedia list](https://bulbapedia.bulbagarden.net/wiki/List_of_Pok%C3%A9mon_by_catch_rate#Changes_to_catch_rate), the capture rate for many Pokemon has changed both between gens, and between games. I think this is something the API should support if there's going to be an attempt to have past types, past stats, and past moves.