The minor leagues have gone through significant restructuring a couple of times (1990 and 2020), so we can't statically map each league to a level. This function takes a vector of years and returns a mapping from league_id to level for each year.
The minor leagues have gone through significant restructuring a couple of times (1990 and 2020), so we can't statically map each league to a level. This function takes a vector of years and returns a mapping from league_id to level for each year.