Before the advent of the Open era of tennis competitions in April 1968, only amateurs were allowed to compete in established tournaments, including the four majors. There was no prize money and players were compensated for travel expenses only. However many top tennis players turned professional to play legally for prize money in the years before the open era. They played in separate professional events, mostly on tours involving head-to-head competition, but also in professional tournaments as the biggest events on the pro tour.[1] Professional tournaments, in particular the professional majors, usually only had a men's draw.