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
Rules of snooker "on" in that order. During this phase, the colours are not replaced on the table after being legally potted, however, any colour potted as the result of a foul is re-spotted. After all six colours have been potted, the player with the higher score wins the frame (but see below for end-of-frame scenarios). A foul is a shot or action by the striker which is against the rules of the game. When a foul is made during a shot, the player's turn ends and they receive no points for any balls potted on that shot. Common fouls are: When a