In 1902 the first football game was held (between the University of Michigan and Stanford University) in Tournament Park, but chariot races and other contests were thereafter substituted, and football was not introduced as the annual contest until 1916. The Rose Bowl stadium opened in 1922, in time for the 1923 game. (Because of restrictions on crowds on the West Coast during World War II, the 1942 game was relocated to Durham, N.C.) Originally, the championship team of the Pacific Coast Intercollegiate Athletic Conference (now the Pacific-10 (Pacific-10 Conference)) simply invited a winning team from anywhere in the eastern United States to be its opponent. Beginning in 1947, however, the Rose Bowl brought together teams from the Big Ten (Big Ten Conference) (in the Midwest) and Pacific-10 (Pacific-10 Conference) conferences and their forerunners; with the advent of the BCS system, the bowl has maintained its tie-in with these two conferences, generally matching their champions unless one or both of them play in the national championship. (Under the format the BCS used until 2007, each year, on a rotating basis, one of the predicating bowls became the national championship game, so that in 2002 the Rose Bowl was played by the Universities of Miami and Nebraska and in 2006 by the Universities of Texas and Southern California.)