Snooker (British English pronunciation:  /ˈsnuːkər/) is a cue sport that is played on a green or other coloured baize-covered table with pockets in each of the four corners and in the middle of each of the long side cushions. The (baize) cloth on a snooker table has a directional nap running from the balk end of the table towards the end with the (black ball) spot. This affects how a ball rolls depending on which direction it is hit or shot. A regular (full-size) table is 12 × 6 ft (3.7 × 1.8 m). It is played using a cue and 22 snooker balls: one white cue ball, 15 red balls worth one point each, and six balls of different colours: yellow (2 points), green (3), brown (4), blue (5), pink (6) and black (7). A player (or team) wins a frame (individual game) of snooker by scoring more points than the opponent(s), using the cue ball to pot the red and coloured balls. A player wins a match when a certain number of frames have been won.

Snooker, generally regarded as having been invented in India by British Army officers, is popular in many of the English-speaking and Commonwealth countries, with top professional players attaining multi-million pound career earnings from the game. The sport is now increasingly popular in China.

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.