I wouldn't call Bellator a minor league.. they are pretty much #3 in MMA right now.. behind UFC and Strikeforce.. and they are only in their 2nd year. They have top fighters like Eddie Alvarez (#3 Lightweight in the World) and Roger Huerta (who just got beat in a great fight with Pat Curran.. cousin of Jeff Curran.. in a 3 round decision).
They fight in a tournament setting to determine who will fight for the championship against the current champion for each weight class. Last year was their first tournament, and each division determined a champion. They had 3 divisions last year - Lightweight (155 lbs), Welterweight (170 lbs), and Middleweight (185 lbs).. this year they added the Featherweight division (145 lbs) to their tournament schedule.