By Michael Brown, Sentinel Sports WriterThe Texas Longhorns’ upset win on the road against fifth ranked Nebraska proved to be a harbinger of things to come last Saturday, as six other top 25 teams fell to lower ranked opponents throughout the evening.Life as a top ranked team can be hazardous indeed, especially when schools have to travel to hostile environments where mistakes, crowd noise and officiating tend to work in favor of the host team.Need proof?Ask No. 1 ranked Ohio State about its Wisconsin trip. While many fans and pundits figured the Buckeyes were a shoo-in to run the table in the Big Ten, the Badgers had other ideas as it jumped out to a 21-3 first half lead and never relented in the upset.Tenth ranked South Carolina, after upsetting No. 1 Alabama the week prior, was upset on the road against Kentucky, 31-28, as the Wildcats rallied and scored 14 fourth quarter points.Nevada, Air Force and Oregon State also dropped games on the road, and the rebuilding No. 22 ranked Florida Gators lost at home to Mississippi State, 10-7. The weekend also featured the unveiling of the first Bowl Championship Series rankings. And, to no one’s surprise, the controversial system which determines who plays for the national title, sparked debate and turned heads in the college football world, when it was revealed that the Oklahoma Sooners were No. 1, despite being ranked lower in the human polls.Impressive performances The two biggest upsets of the day weren’t exactly picture-perfect all-around great performances by the winners, but they both featured stingy defenses that contained two Heisman candidate quarterbacks.First, Wisconsin’s 31-18 win over Ohio State was helped by physical play on both of its lines as the Badgers ran for 184 yards and bullied the Buckeyes’ offensive line, which rattled quarterback Terrelle Pryor.Pryor finished 14 of 28 passing with 156 yards and no touchdowns, but more importantly for Wisconsin, its defenders played disciplined and clogged lanes the quarterback would usually exploit. Pryor was bottled up for 56 yards rushing on 18 carries and never was comfortable in the pocket due to Wisconsin‘s pressure.Texas employed a similar strategy against Nebraska’s freshman quarterback Taylor Martinez, who entered the game averaging 147 yards per game rushing and 11 yards per carry.After the ‘Horns jumped out to a 17-3 lead, the defense carried it to a 20-13 victory. The disappointing Longhorns’ anemic offense wasn’t spectacular, but it didn’t have to be as its defense limited Nebraska to 202 total yards, 292 below its season’s average.Martinez, who finished 4 of 12 for 62 yards, was so flustered, head coach Bo Pelini pulled him in the third quarter for the back up.The impressive performance segment of my weekly column is usually reserved for winning teams, but Auburn and Arkansas will both share honors this week. In a historic SEC offensive showcase, Auburn outscored Arkansas, 65-43, to remain undefeated. The combined 108 points was the highest-scoring regulation game in SEC history. Both teams amassed 1036 yards and only punted five times.Auburn led 37-35 after three quarters, but blew the game open by scoring 28 points in the fourth. The Tigers’ quarterback, Cam Newton, accounted for 329 total yards and four touchdowns.BCS rankings Through several weeks of human vs. human competition on the gridiron, and human voters in the Coaches and Associated Press polls weighing in with their opinions about who is No. 1, the BCS computers chimed in this week-throwing the rankings into a tailspin.The BCS determines its standings by averaging the percent totals of the Harris Interactive, USA Today, Coaches and Computer polls, which always makes for some interesting debate.For instance, Oklahoma and LSU were ranked No. 1 and 2 by the BCS, respectively, shocking many despite both teams being undefeated.Oklahoma, which has struggled to defeat the likes of Cincinnati, Air Force and Utah State, is fourth in the Harris and third in the USA Today. LSU, which has looked anything but elite this season, is ranked sixth in both human polls.Oregon and Boise State on the other hand, who are ranked No. 1 and 2 in both human polls, respectively, received no love from the Computers. Despite dominating everyone of its opponents, Oregon is ranked eight by the Computers and Boise State came in at seventh.Auburn checked in at third followed by Michigan State and TCU. Preseason national title favorites Alabama and Ohio State are ranked 12th and 14th.With so much more football in front of us, it seems premature to get hysterical about the BCS. All of the top teams are unbeaten which is sure to change over the next few weeks, and consider this, only once in the system’s 12-year existence have the top teams ranked at the outset, played for the national title. The last time it occurred was in 2005 when Texas faced USC.Big games this weekendDuring the past two weeks, both Alabama and Ohio State have fallen from the top spot by losing on the road to conference opponents. Will Oklahoma be the third? Yes, if the 11th ranked Missouri Tigers have a say.The Sooners’ young defense will be put to the test as Missouri quarterback Blaine Gabbert attempts to guide his team to its first big win this season, and improve on its 6-0 record.The nation will also find out a lot about No. 6 LSU as it visits No. 4 Auburn in a battle of the unbeaten.Auburn’s prolific offense may prove to be too much for LSU which has struggled on offense, and now alternates quarterbacks Jarrett Lee and Jordan Jefferson.TCU could have its hands full at home against Air Force, which may have been looking ahead to this game after being upset by San Diego State last Saturday. Air Force’s vaunted running game is the best in the nation averaging 347 yards per game. The Horned Frogs will counter with the nation’s No. 1 defense, which allows 9 points a game.UCLA at No. 2 Oregon on Thursday, along with Saturday games featuring 13th ranked Wisconsin at No. 15 Iowa and 16th ranked Nebraska at No. 14 Oklahoma State are other games to keep an eye on.