More recently, the Shaughnessy playoff system has been adopted outside of North America. In English rugby union, the format is currently used to determine the winner of the Premiership, and from 2012–13 through to 2016–17 was also used in the second-level RFU Championship to determine the team to be promoted to the Premiership. The Premiership and Championship formats differ only in the number of games contested—the Premiership playoff uses one-off matches, while all matches in the Championship playoff were two-legged. The Premier 15s, launched in autumn 2017 as the new top flight of English women's rugby, uses the same playoff format as the Premiership. The Celtic League in Ireland, Scotland and Wales, now known as Pro14, adopted a system identical to that of the Premiership starting in 2009–10, the season before that league expanded to include two teams from Italy. The Shaughnessy system was replaced by a six-team playoff when two South African sides joined the league in 2017–18, bringing it to its current 14-team roster.