 American rotation (AR) is a modern, tournament-focused, , variant, devised in 2013 by US professional player and instructor Joe Tucker, to increase the difficulty of the game.It uses a different scoring system from traditional rotation.The sport is played in the US and Canada, is governed by the American Billiard Club (ABC), an affiliate of CueSports International (CSI), and is the subject of regular American Rotation Championship Series (ARCS) tournaments.