The BCS is the Bowl Championship Series, college football's answer to a question no one asked. It works like this:
1. At the end of the regular season the #1 and #2 ranked teams play for the national championship in a bowl game that rotates from location to location.
2. The team rankings are determined by a poll of college football coaches (who notoriously don't vote themselves and have a toady do it for them) and a computer. Or series of computers. I'm not sure which. Regardless of whether it's one computer or several they appear to all be using Windows ME and an AMD K6 processor because they are stuck in the past.
Years ago college football was something fun that was regional. If your team won their conference they would play in a bowl game against a team from another region that had won its conference. Think Ohio State versue USC in the Rose Bowl. But over time college football became big business and very lucrative for the universities. More lucrative for bowl chairpersons who wear horrible suites with white leather shoes. Thus, a national ranking system was born (including such things as "strength of schedule", which is determined by a computer programmed by one of those guys in horrible suits, most likely) and with it, the Bowl Championship Series. See, the various rich white guys in bad suits run these bowls and they invite two teams to play in them each year and make a ton of money. Sure, the schools get some scratch too, but these bowl people are today's version of the robber barons of the railroad heyday in years gone by.
Most people who follow college football want a national playoff, like college basketball does. The powers that be stubbornly refuse to do this because the monetary flow of their cash cows would be lightened and because they are complete jerks. They offer arguments like, "Things are just fine they way they are" and "The BCS gives us the best of all possible scenarios", but they offer no evidence to accompany their claims. Why? Because no such evidence exists. As things stand now smaller conferences have ZERO chance to play for the national championship (I offer Utah and Boise State as Exhibits A and B). And lesser BCS conferences, like the Big East, barely have any better a chance of playing for the national championship either. If, for instance, Florida and West Virginia were to both go undefeated, and Texas had won the Big 12 conference championship game, but had 1 loss on their regular season record, the national championship game would be Florida vs. Texas. Everyone knows that, including the horrid suit-wearing power brokers that comprise the BCS. It's not fair and it stinks, but until the NCAA and the various conferences decide to set aside the almighty dollar and stand up for what is right we are stuck with this mess.
Of course, several members of the federal government have poked their gin-laden noses into this and threatened to intervene and force a playoff format. The problem with that is that A) they should be focusing their time and energies on righting the economy (and various other woes our nation faces) and B) the government cannot properly run or manage anything because it, as an institution, is corrupt and inept.