BATON ROUGE, La. — The Bowl Championship Series released its first rankings of the season Sunday, and on the surface, the list highlighted what most expected: Alabama in the top slot, the decisive favorite, the defending champion on course to repeat, followed by everybody else.

It was the “everybody else” category that provided the intrigue.

Florida sat in second, one spot ahead of Oregon. Behind the Ducks, two surprise teams, Kansas State and Notre Dame, settled into fourth and fifth. There were four SEC teams (Alabama, Florida, LSU and South Carolina) in the top 10, which was expected, and three Pac-12 teams (Oregon, Oregon State and Southern California), which was not.

All this rankings business, of course, meant little this early in the season. It provided fodder for sports radio and fan bases across the country; an early gauge, but not much more.

Proof of that occurred here Saturday, when LSU, left for dead after its loss to Florida, hosted undefeated South Carolina. The Tigers, behind uninspired quarterback play and an ineffective offense, seemed ripe for another upset from the upstart Gamecocks.

Instead, Tiger Stadium shook behind a capacity crowd and LSU’s celebrated defense played like an NFL unit. South Carolina’s quarterback, Connor Shaw, labeled the Tigers’ defense the most physical he ever faced. Running back Marcus Lattimore, who managed 2.7 yards a carry, called LSU’s defensive line “probably the best we’ve seen.”

“Some of our guys got smashed last night,” Steve Spurrier, the South Carolina coach, said on a Sunday conference call. “They acted like they were afraid of LSU. Football is a game of emotion. It’s who’s got more fire in their tank. LSU had a lot more.”

Florida leapt past Oregon based on its strength of schedule, behind victories at Tennessee and at Texas A&M and the victory over LSU at home. This registered as a mild surprise, if only because the Ducks ranked ahead of Florida in the polls.

In the next two weeks, though, Florida hosts South Carolina and meets Georgia, teams ranked 7th and 11th in the BCS standings. Then there is the matter of Florida State, ranked 14th in the BCS, which plays Florida in the season finale, along with a potential matchup for Florida with Alabama in the SEC title game.

Notre Dame, similarly, slid into the fifth position by virtue of its victories against Michigan, Michigan State, Miami and Stanford. The Fighting Irish, whose remaining schedule includes Oklahoma and Southern Cal, appear to be in good position for a national championship run, if Notre Dame can leap over Oregon down the line.

The most surprising BCS team, in fourth, was Kansas State. The Wildcats beat up on Miami, beat Oklahoma and won each of their six games. But the degree of difficulty will increase in the weeks ahead, with games against West Virginia (No. 13 in the BCS) and Texas Tech (No. 17).

The rankings, while a solid early season gauge, fail to account for the number of games remaining for top teams. Alabama will play Mississippi State (No. 12), LSU and possibly Florida in the SEC title game. Oregon will play Southern California (No. 10) and Oregon State (No. 8).

Florida, beyond its tests against South Carolina and Georgia, would also play in the SEC title game, should it win the rest of its games. Then there is Kansas State, which, despite its schedule, lacks the kind of showcase game that would allow the Wildcats to leapfrog an undefeated Oregon or Notre Dame.

Those questions will be answered in the weeks to come. Is Mississippi State for real? Is Florida? Can Oregon win out in the Pac-12?

For the all the speculation, though, Alabama seems to stand alone. The Crimson Tide have quietly advanced to where everyone expected. Alabama’s defense has yet to allow more than 14 points in a game. The Tide’s next three games — at Tennessee, against Mississippi State, at LSU — will further define their title defense.

But at this point, it seems like Alabama’s championship to lose.

“I have a sense that everybody is hoping Alabama will take a step back,” said Gary Danielson, a CBS Sports college football analyst. “I don’t know if a lot of teams deep down in their hearts really think they can match up with Alabama.”

Thus the 2012 college football season continues, so close to the new four-team playoff format but not there yet. This season could end with three or four undefeated teams, perhaps Alabama, Oregon, Notre Dame and Kansas State. Perhaps not.

But as LSU proved Saturday night, the season is a long one.

“We executed a lot better,” quarterback Zach Mettenberger said Saturday. “From here on out, we just got to show up with the same mentality and attitude.”