For which period? If you are talking about the Giancana years, it would be Ricca as the chairman with something indicating that Giancana was a front boss, or day-to-day boss with authority over the capos. Accardo could be thought of as Paul Ricca's partner at the top but he always deferred to Paul while Paul was healthy, so it is in that sense that Accardo was Paul's #2. Accardo respected Paul like no one else. During the Giancana years, Accardo did not try to go legit or anything, but he reduced his day-to-day involvement significantly. So on a chart something roughly equivalent to consigliere with Cerone bearding for him on matters concerning him.