Geographic variations exist in the United States and Brazil, while speed versions of the standard game have been developed in the United Kingdom. American snooker is an amateur version of the game played almost exclusively in the United States. With simplified rules and generally played on smaller tables, this variant dates back to 1925. "Sinuca brasileira" (or "Brazilian snooker") is a variant of snooker played exclusively in Brazil, with fully divergent rules from the standard game, and using only one red ball instead of fifteen. At the start of the game, the single red is positioned halfway between the pink ball and the side cushion and the break-off shot cannot be used to pot the red or place the opponent in a snooker. The Snooker Shoot Out is a variant snooker tournament, first staged in 1990, featuring single-frame matches for an accelerated format. The idea was resurrected in 2011 with a modified version that was added to the professional tour in the 2010–11 season and upgraded to a ranking event in 2017.