The following season, the Rose Bowl, Pac-10, and Big Ten joined the other bowls and major conferences to form the Bowl Championship Series. The BCS attempted to match the two highest ranked teams in the country based upon calculations from various sources, including statistics and coaches' polls, with one of the four bowl games in the consortium (the Rose Bowl, Fiesta Bowl, Sugar Bowl, and Orange Bowl) rotating the role of "national championship", or beginning in 2006, a dedicated BCS Championship Game rotated among the BCS venues. The BCS Championship Game, while separate from the four main bowls, was still rotated among their sites. The Coaches Poll was contractually obligated to recognize the winner of the game as its national champion. However, other polls such as the AP Poll may deviate and pick a different team, particularly in years when multiple teams were equally worthy of reaching the game. For example, in 2003, one-loss LSU won the BCS National Championship over Oklahoma, but the AP crowned one-loss USC champion after its Rose Bowl win.