How many members are in theat club?
SELECT count ( * )  from club as T1 join member_of_club as T2 on T1.clubid  =  T2.clubid group by T2.clubid order by count ( * )  desc limit 1
counting members in the club refers to COUNT(*); joining two tables (club and member_of_club) indicates a relationship through a common clubid; grouping by clubid and ordering by count in descending order with limit 1 to find the club with the most members.