American pool is a term used in the
United Kingdom, and sometimes more broadly outside
North America, to refer to
pool (pocket billiards)
cue sports that make use of formerly American-style and now professionally
world-standardised numbered
billiard balls that have a standard diameter of 57 mm (2+1⁄4 in), as opposed to British-style unnumbered 56 mm (2+3⁄16 in) balls. Other "American" pool differences from British-style pool include larger
pockets to accommodate the bigger balls, and
diamond system markings on the
rails.
The term may apply to any pool game variety using such a ball set, and is commonly applied especially to the most internationally competitive of these sports:
Eight-ball, the most commonly played form of pool (as distinct from
blackball, a.k.a. British eightball pool)
Nine-ball, the leading professional variant of pool, with historical roots in the United States in the 1920s. Played globally by professional's such as Darren Appleton and Shane Van Boeing.
Ten-ball, a rotation game very similar to nine-ball, but more difficult, using ten balls instead of nine, and played
called-shot
Straight pool (a.k.a. 14.1 continuous), formerly the common sport of championship competition until overtaken by faster-playing games like nine-ball
One-pocket, an extremely challenging game in which each player must make all shots into a single pocket.