In 1969, the World Snooker Championship became a single elimination tournament, replacing the previous challenge format; this marks the start of the professional game's "modern era." Six years later, a non-ranking invitational event, the Masters, was introduced; there were 10 competitors in the inaugural Masters in 1975, which later increased to 16 players. John Spencer won the 1975 Masters tournament, becoming the first person to win two Triple Crown events, having won the world championships in 1969 and 1971. The following year, Ray Reardon won both the Masters and World Championship in the same season.