Until the year 1960 the World Championships were held after every two years and from there on after every four years. On the year 1960 women were allowed to participate in a World Championship tournament tough outside the official competition program.
Kuni aastani 1960 peeti maailmameistrivõistlusi iga kahe aasta tagant, sealt edasi tänaseni aga iga nelja aasta tagant. 1960-ndal aastal said esimest korda MM-il osaleda ka naised, kuigi väljaspool ametlikku võistluskava.