Poll Average: Both the AP and ESPN-USA Today coaches polls are averaged to make a number which is the poll average. Computer Average: An average of the the rankings of a team in 7 different computer polls are gathered, with the poll in which the team is lowest ranked being dropped. This creates the computer average. Schedule rank: This is the team's strength of schedule divided by 25. A teams strength of schedule is calculated by win/loss record of opponents (66.6%) and cumulative win/loss record of team's opponents opponents (33.3%). Losses: One point is added for every loss the team has suffered during the season. Quality Win Component: If a team beats a team which is in the top 10 in the BCS standings, a range of 1 to .1 points will be subtracted from their total. Beating the #1 ranked team will result in a loss of 1 point (remember, losing points is a good thing), a #5 team will result in a loss of .5 points and the #10th ranked team would result in a loss of .1 points. If you beat a team twice during the season, you may only be rewarded quality win points once--or, possibly, not at all. Quality win points are calculated by the final BCS standings (so if you beat the #1 team in the second week of the season, you may not be entitled to .8 points at the end of the season).
The exact formula of how the final point total for any team is calculated is not public information, but it is known that it is derived from these factors. Some have been able to guess the formula and thus predict the results before the official standings are released.
Bowl Games
There are 4 bowl games that are considered "BCS Bowl Games". They include the Sugar Bowl, the Rose Bowl, the Fiesta Bowl, and the Orange Bowl.
Two of the bowls are played January 1st, one on January 2nd and the national championship is played on January 4th. The championship bowl is rotated between the different bowls, for example, the Sugar Bowl will have the national championship game once every four years.
The national championship bowl game is forced to select the top 2 BCS-ranked teams. The winners of the 6 major conferences (Big East, ACC, SEC, Big 12, Big 10, Pac 10) are guaranteed automatic BCS bowl appearances.
There are 2 "at-large" berths which can be either granted to teams in those conferences who did not win their championship or to teams belonging to mid-major conferences. Also, in theory, a team who did not win its conference could play in the national championship game. This happened in practice twice. In the 2003 season, Oklahoma went to the BCS title game despite being blown out in the Big 12 championship game by Kansas State. In 2001, Nebraska made the BCS title game despite not even qualifying for the Big 12 championship game.
Despite the possibility of an "at-large" berth being granted to a mid-major team, this has never happened; see BCS Controversy for more on that.
The BCS bowls are required to have the top 6 BCS ranked teams in their games, but this requirement presumably falls lower than the conference requirement (IE if the 6th ranked team had to be left out for an 11th ranked team who won its major conference to be admitted, the 11th ranked would be admitted).
The worst year probably was the 2003-2004 season, when 3 teams, Oklahoma, LSU, and USC finished the season with one loss. (Two non-BCS teams, Miami University and Boise State, also finished with one loss, but neither was in contention for a BCS bowl berth, much less the championship.) USC was #1 in both the AP and ESPN-USA Today Coaches poll, but had a 2.67 computer poll ranking and had the 37th ranking schedule. LSU had a #2 poll average, a 1.83 computer average, and a 29th rank of schedule. Oklahoma had a #3 poll average, a 1.17 computer average, and the 11th ranking schedule along with a quality win of .5. The final numeric averages for the teams were as follows (keep in mind anything within 1 is close)
BCS Controversy
The BCS has come under fire, partly due to its existence; the formula has to determine which 2 nationwide teams are fit to be play for the national championship. Rarely is there a year where the 2 top teams in the nation are clear-cut choices.
Therefore, Oklahoma and LSU played each other in that year's title game, the Sugar Bowl, with LSU winning. The BCS was highly criticized since USC had been ranked #1 by humans but had somehow fallen to #3 in a computer average like the BCS. Since USC beat Michigan in the Rose Bowl, the writers who vote in the AP poll had the opportunity to vote USC as their national champion, which they did. However, the coaches were contractually bound to vote for the Sugar Bowl winner (LSU). Three coaches violated the agreement and voted USC #1, but all other coaches voted for LSU, giving the Tigers the other half of the national title.
The BCS has also been criticized for locking out mid-major programs. No mid-major program has gone to a BCS bowl and some have accused the BCS and associating bowls of having a monopoly of sorts on the top bowls. There were even congressional hearings on the issue. It would likely take a qualified mid-major program being locked out of the BCS when they were obviously deserving for this issue to be looked at more closely. Incidentally, only once since 1980 has a school outside of today's BCS played in one of the current BCS bowls (Louisville in the 1991 Fiesta Bowl).
Some, including ESPN's Lee Corso have suggested that the BCS reincorporate margin of victory into the rankings, a factor which would have changed the 2003-2004 final rankings (had USC and Oklahoma in the championship).
The BCS is officially sponsored by ABC