https://www.cnet.com/news/wwe-royal-rumble-2019-start-time-how-to-watch-confirmed-entrants-full-match-card-and-more/

Ronda Rousey is one of the biggest mainstream draws in WWE right now. 

Each Royal Rumble match consists of 30 superstars. The match starts with two combatants and another entrant enters the match every two minutes. This list of confirmed entrants will be updated as the event approaches.