The Bowl Championship Series has been in place since 1998. It is a formula that selects the college football matches for the five prestigious games the Tostitos Fiesta Bowl, the FedEx Orange Bowl, the Nokia Sugar Bowl, and The Rose Bowl. The teams selected include the conference champion from each of the six BCS conferences, which consist of the Atlantic Coast Conference, Big 12 Conference, Big East Conference, Big Ten Conference, Pacific Ten Conference, and the Southeastern Conference, plus two "at-large" selections from non BCS NCAA Division 1-A Football Conferences, which includes the Western Athletic Conference. The top-ranked and second-ranked teams play in the BCS National Championship Game in order to crown an unofficial NCAA Division I-A national football champion.

The formula was revamped after the 2003-04 controversy in which the top team in the human polls, the University of Southern California, was denied a place in the title game. Schedule strength, losses, and quality wins are no longer considered distinct components in the formula. However, human voters remain free to consider any factors they feel valid. The formula was made public, consisting of an arithmetic average of the following three statistics:

Harris Interactive College Football Poll: This poll consists of a panel of former players, coaches, administrators and current and former media who submit rankings of college teams each week. A team's poll number is the percentage of the possible points it could receive in the poll.
Coaches' Poll: This is calculated in the same manner as the Harris Interactive College Football Poll number.
Computer Average: The BCS uses six computer rating systems (Anderson-Hester, Billingsley, Colley, Massey, Sagarin, and Wolfe) and drops the highest and lowest ranking of each team. Then, it gives a team 25 points for a Number 1 ranking in an individual system, 24 points for Number 2, and so on. Each team's ranking points are then added, making the number compatible with the percentages from the two polls.
More changes have taken place in the BCS for the 2006-07 season. A game, separate from the games already in the BCS, matching the top two teams in the BCS rankings will take place at the site of one of the Bowl Games one week after the Bowl Game as the current rotation will continue. Due to that, the addition of two more "at large" teams will take place. Also, a new rule states that if a non-BCS team above a rating of 16th is more highly rated than a BCS conference champion, the non-BCS team will be selected.

http://www.arbiteronline.com/vnews/displ...4602caf8fe