Name fighters who went through the ranks quickly without much experience.

George Foreman: only fought for a few years and won the Olympics then fought 3 more years and won the HW title. He hadn't been boxing long at all (comparatively) at the time he was thought to be unstoppable.

Billy Conn: started at the age of 16 with no amateur experience and fought his way through tough fighters to win the light HW title at age 21. He then fought Joe Louis at 23 being outweighed by 25 pounds and got knocked out at the end while being ahead on the scorecards. It's pretty amazing since he really hadn't boxed for that long and was just thrown to the wolves at the beginning of his career.

Who else?