The Welsh Rugby Union Division One West (also called the SWALEC Division One West for sponsorship reasons) is a rugby union league in Wales first implemented for the 1995/96 season.
During the course of a season (which lasts from September to April) each club plays the others twice, once at their home ground and once at that of their opponents for a total of 22 games for each club, with a total of 132 games in each season.
At the end of each season, the club which finishes top (as determined by the above criteria) is crowned as champion.
Instead the seven clubs who are not promoted into the new National Championship via the meritocracy criteria detailed above will remain in Division One West for the 2012/13 season.
[1] The sponsorship is a three-year deal that will continue until the 2010/11 season at a cost of £1 million (GBP).