Snooker in 1977: Snookers and the free ball

Twenty-two balls, six pockets barely wider than they are, and the most pitiless scoreboard in sport. 12 ft by 6 ft — a playing surface of 3,569 mm by 1,778 mm, the largest in mainstream cue sports 22: one white cue ball, 15 reds worth 1 point each, and six colours worth 2 to 7 147 — fifteen reds each followed by the black, then the six colours in sequence

Devised by British Army officers in Jabalpur, India, in 1875; brought to Britain in the 1880s World Championship, staged at Sheffield's Crucible Theatre since 1977; 500,000 pounds to the winner Joe Davis with 15 (1927-1946); Ronnie O'Sullivan and Stephen Hendry share the modern record of 7

Snooker is the slowest-burning of the great cue sports and the most punishing. Twenty-two balls sit on a table twelve feet by six, with templated pockets only a few millimetres wider than the balls themselves, and the striker must alternate red and colour, red and colour, assembling a score the opponent can only sit and watch. A perfect visit — fifteen reds, fifteen blacks and the six colours in order — is worth exactly 147, and every one made in professional competition is logged as an event in its own right. The game was invented by bored British Army officers in India in 1875 and codified in Britain a generation later.