Here's a look at the American Conference power rankings through the first six weeks of the season.
1. USF (5-0, 2-0 AAC): Thanks to Iowa State's 38-31 upset of Oklahoma, the No. 18 Bulls own the distinction of the longest current stretch without a loss (dating to Oct. 21, 2016) of any FBS team. They enter Saturday's homecoming game against Cincinnati on a 10-game win streak, second-longest in the nation behind Clemson (11). USF is coming off a bye week during which its two top rushers -- seniors D'Ernest Johnson and Darius Tice -- wore protective boots for minor ailments.