Pool's name may trace to a medieval game of stoning a chicken
Nobody knows for sure why pool is called pool. One theory from the Oxford English Dictionary points to the French poule, hen, and a medieval game in which players chipped into a shared pot and threw stones at a live chicken, the first to hit it taking the money.
The simpler alternative is the verb to pool, as in combining stakes. The word first described a billiards-type game in a Virginia newspaper in 1797. The dictionary's earliest specific sense, a game where each player uses a differently coloured cue ball to pocket opponents' balls in order, winner taking all, is obsolete, and across the British Empire for most of the 19th century pool meant the game of life pool. In the United States the name attached itself to each new pocket game, so despite the industry's preference for pocket billiards, ordinary speech kept pool.
Pocket billiards is technically broader, taking in snooker, Russian pyramid and kaisa, which nobody calls pool. Pool proper is played on a table with six pockets along the rails, and popular games range from nine-ball, ten-ball and seven-ball to bank pool, one-pocket, straight pool and blackball. Eight-ball is played most and is often treated as a synonym for the sport. Hybrids mixing pool with carom billiards include bottle pool, cowboy pool and English billiards.
Apart from one-pocket, today's pool games descend from two English imports of the 19th century. English billiards became American four-ball billiards by adding a red ball for more scoring chances, and it led the field in the mid-1800s until straight rail overtook it; its last professional tournament was in 1876, and cowboy pool is a survivor of that line. Pyramid pool mattered more. Its variant fifteen-ball pool caught on by 1850, and in 1888 both gave way to continuous pool, which led to straight pool in 1910. Kelly pool and eight-ball appeared around 1900.
The balls changed look too. Object balls were once all deep red, told apart only by numbers. English pyramid and life pool players first adopted different colours, and by 1889 the familiar multicoloured set had arrived, with stripes added last to split solids from striped balls.
Source: Pool (cue sports)
