Editing Nine-ball (section)

==Derived games==
{{main article|Seven-ball|Ten-ball}}
[[File:Six-ball rack 2.jpg|thumb|right|150px|A six-ball rack, played with the leftovers of a nine-ball game; the 10 ball (the lowest) is at the apex, and the 15 is the money ball]]
Several games have been derived from nine-ball. Six-ball is essentially identical to nine-ball but with three fewer balls, which are racked in a three-row triangle, with the money ball placed in the center of the back row.<ref name="Shamos 1999_JXJy2">{{Shamos 1999|page=89-90}}</ref> According to [[Rudolf Wanderone]], the game arose in early 20th century billiard halls; halls charged for matches by the 15 ball rack rather than by table, so players of nine-ball had six balls left over.<ref name="Shamos 1999_JXJy2" /> For this reason, the game is often played with the balls numbered between 10 and 15, with the 15 ball as the money ball.<ref name="Shamos 1999_JXJy2" />

[[File:Seven-ball hex rack with black 7 ball.jpg|thumb|left|150px|Racking a seven-ball game with a special hexagonal rack and black-striped 7 ball.]]
[[Seven-ball]] is also similar to nine-ball, though it differs in two key ways: the game uses only seven object balls, which are racked in a hexagon, and players are restricted to pocketing the money ball on their designated side of the table. William D. Clayton is credited with the game's invention in the early 1980s.<ref>{{cite book |last=Shamos |first=Michael Ian |year=1993 |title=The Illustrated Encyclopedia of Billiards |publisher=Lyons & Burford |location=[[Manhattan|New York, NY]] |pages=[https://archive.org/details/illustratedencyc0000sham/page/206 206] |isbn=1-55821-219-1 |url-access=registration |url=https://archive.org/details/illustratedencyc0000sham/page/206}}</ref> While not a common game, it was featured on television broadcaster [[ESPN]]'s ''Sudden Death Seven-ball'' which aired in the early 2000s.<ref name="Shamos 1999_JXJy2" />

[[File:Ten-ball rack.jpg|thumb|right|150px|A valid ten-ball rack; the 1 is at the apex on the {{cuegloss|foot spot}}, and the 10 (the {{Cuegloss|Money ball|money ball}}) is in the center.]]
The most common derivative game is the game of [[ten-ball]]. The game is a more stringent variant, using ten balls in which all pocketed balls must be {{cuegloss|call shot|called}}. Unlike in nine-ball, the money ball cannot be pocketed on the break for an instant win. Due to its more challenging nature, and the fact that there is no publicly known technique for reliably pocketing specific object balls on the break shot, there have been suggestions among the professional circuit that ten-ball should replace nine-ball as the pro game of choice,<ref name="Jewett BD 2008-02" /> especially since the rise of the nine-ball soft break, which is still legal in most international and non-European competition.<ref name="Jewett BD 2008-02" /> Ten-ball has its own world championship known as the [[WPA World Ten-ball Championship]].<ref>{{Cite web |title=Predator World 10-Ball Championship – Las Vegas (2019-07-22) |work=WPA Pool |access-date=6 January 2020 |url=https://wpapool.com/event/world-10-ball-championship-las-vegas/ |archive-url=https://web.archive.org/web/20190628153752/https://wpapool.com/event/world-10-ball-championship-las-vegas/ |archive-date=28 June 2019 |url-status=live}}</ref>