Where are the default rosters stored?

When I start the game, it always loads the default rosters rather than the custom rosters. Where is the file for the default roster? I'd like to replace it with the custom roster so that it loads that on startup.

roster.iff file either in the online data, downloaded from 2K, or in the main folder. There is no way to customize that file, you gotta spend those agonizing 5 seconds to load a custom roster.