After 17 straight weeks atop the ESPN Stats & Info Conference Power Rankings -- a rankings system that uses a formula that equally weighs the rankings from the AP Poll and a compilation of available BCS computer rankings in order to determine which conference is the best and worst in the country -- the SEC has been dethroned.

The Big 12 is on top of the Week 3 Conference Power Rankings after big wins by Oklahoma and Texas over non-conference foes this past weekend. Overall, the Big 12 is 23-2 in games outside of the conference (SEC is 22-4) and have five teams ranked in the AP Top 25 (tied with SEC for most teams ranked in the poll). Big wins over Florida State, TCU, Arizona and UCLA in the first three weeks have vaulted the Big 12 over the SEC as the top conference in the country.

After finishing in second place in last season's final rankings, the Pac-12 is the fourth-ranked conference after three weeks of 2011. The Pac-12 went 5-4 in non-conference games this past weekend as UCLA, Arizona State, Washington and Washington State all lost. With no clear power-house coming out the Pac-12 South Division, the conference is in jeopardy of being jumped by the ACC or the Big East in upcoming weeks.

The ACC was tested at home this weekend and came out with two big non-conference wins that helped the conference in the rankings. Clemson’s victory of defending national champion Auburn and Miami’s win over Ohio State proved that the ACC is still a top conference in the country.

Similarly, close losses to Oklahoma and West Virginia (top teams in the Big 12 and Big East) did not hurt the ACC. Florida State only fell from 5th to 11th place in the AP Poll and Maryland also received AP votes (though was not ranked). Georgia Tech also jumped into the rankings after a big win over Kansas where they put 768 total yards.

Just as the ACC was tested last weekend, the Big East will have its chance to jump in the rankings with LSU, NC State and Notre Dame visiting West Virginia, Cincinnati and Pittsburgh respectively. With uncertainty surrounding the Big East and conference realignment, this weekend could be big for the Big East to prove its worth.

For a brief recap on how we rank the conferences, click here.

ESPN Stats & Info Week 3 Conference Power Rankings