 Complete the following phrase:  He began working backstage as a road agent and right-hand man to WWF promoter Vince McMahon, and is credited with inventing and booking the Royal Rumble match. In the late 1990s, he also worked in the talent-relations department. After his retirement, Patterson also worked as a WWF referee. He was selected as the in-ring referee for the main event at the first WrestleMania at Madison Square Garden on 