In its original form, a pair would continue in CTC so long as it kept winning. The prior month's winners were termed the "Champs" and would compete against a new pair, the "Challengers." More recently the contest has been altered: TBW invites a pair to participate for exactly two consecutive months (first as Newcomers, then as Incumbents); if a pair wins at least one of its two matches, it is invited to return at a later time, and possibly take part in a CTC elimination tournament.