Ken Doherty (born 17 September 1969) is an Irish professional snooker player. He is the only player ever to have been world amateur (1989) and world professional champion (1997). He was also World Under-21 champion in 1989.

After two semi-finals in the 1991/92 season (his second as a professional), Doherty reached the final of the 1992 Grand Prix, narrowly losing 10–9 to Jimmy White. In the same event a year later, he lost 6–9 to Peter Ebdon. His first ranking title was the 1993 Welsh Open, enough to take him into the top 16 in the world, where he remained until the 2007/08 season. In the 1994 World Championship he reached the quarter-finals, his only run past the first round before 1997.

Doherty became only the third player from outside the United Kingdom (After Australian Horace Lindrum in 1952 and Canadian Cliff Thorburn in 1980) to win the World Championship when he beat Stephen Hendry 18–12 in the 1997 final. Ken also reached the World Championship final in 1998 (losing to John Higgins) and in 2003, losing narrowly to Mark Williams. The latter run was noted for some outstanding comebacks, including final-frame wins over Graeme Dott and Shaun Murphy, a 13–8 win over John Higgins in a match where Doherty raced ahead 10–0 but Higgins fought back to 10–7, and a semi-final fightback from 9–15 to beat Paul Hunter 17–16. In that championship he played more frames than anyone before or since. In the final, Williams led 11–4 but Doherty fought back to 12–12 and 16–16. In frame 33, Doherty missed the 2nd to final red with a clearance there for the taking. Williams won that crucial frame and the next to prevail 18–16.

Ronald Antonio "Ronnie" O'Sullivan (born 5 December 1975) is an English professional snooker player known for his rapid playing style, and is nicknamed "The Rocket". He has been World Champion on four occasions (2001, 2004, 2008 and 2012) and, with career earnings of over £6 million is second after Stephen Hendry on snooker's all-time prize-money list. O'Sullivan has been the world's no. 1 player on five occasions, and has won a total of 24 ranking titles. He is second, again behind Hendry, on the list of players making the most competitive century breaks, with a total of 678. O'Sullivan has compiled 11 maximum breaks in professional competition, a record which he shares with Hendry. He also holds the record for the fastest maximum break, at 5 minutes 20 seconds.

O'Sullivan is considered by many fans, critics and professionals, including fellow multiple-World Championship winners Hendry and Steve Davis, as the most naturally talented player in the history of the game. He has, however, been involved in a number of controversial incidents during his career.