Cue sports playing nine-ball. Snooker balls are smaller than American-style pool balls with a diameter of 52.5 mm ( in), and come in sets of 22 (15 reds, 6 "", and a cue ball). English billiard balls are the same size as snooker balls and come in sets of three balls (two cue balls and a red, an object ball). Other games, such as bumper pool, have custom ball sets. Billiard balls have been made from many different materials since the start of the game, including clay, bakelite, celluloid, crystallite, ivory, plastic, steel and wood. The dominant material from 1627 until the
Power Snooker the most points overall, irrespective of frames. A 20-second shot clock is imposed on each shot, while additional variants also include power plays, balls and zones, awarding bonus points. The first tournament using the Power Snooker format was played at The O in London on 30 October 2010. Eight players competed for a first prize of £35,000. The format has been sanctioned by, but organised and promoted independently from the World Professional Billiards and Snooker Association (WPBSA) which organises the traditional format of snooker. Barry Hearn stated the hope "that Power Snooker will emulate the success of Twenty20 cricket as