8 Ball Pool
The game of eight-ball arose around 1900 in the United States as a development of pyramid pool, which allows any eight of the fifteen object balls to be pocketed to win. The game arose from two changes made, namely that the 8 ball must be pocketed last to win, and that each player may only pocket half of the other object balls. By 1925 the game was popular enough for the Brunswick-Balke-Collender Company to introduce purpose-made ball sets with seven red, seven yellow, one black ball, and the cue ball, which allowed spectators to more easily see which suit each ball belonged to. (Such colors became standard in the later British-originating variant, blackball). The rules, as officially codified in the Billiard Congress of America's rule book, were periodically revised in the years following.