In professional sumo wrestling, 42 wrestlers compete in a standard top-division tournament roster.
The top division is called makuuchi, and it normally contains 42 ranked wrestlers. They are arranged into the championship rank of yokozuna, the san’yaku ranks of ōzeki, sekiwake, and komusubi, and the maegashira ranks.
A standard tournament gives each makuuchi wrestler 15 bouts, one per day across the 15-day event. Wrestlers do not face every opponent; the scheduling system creates daily pairings while avoiding certain matchups until the later stages.
The number 42 refers to the normal division size, not the number of competitors who appear in every individual bout or the full number of wrestlers at a tournament. Lower divisions have different roster sizes and bout schedules.