(AP) - The defending national champions are still an enigma to many, including themselves. Although second-ranked Ohio State is riding a 23-game win streak, the Buckeyes have yet to face a truly significant challenge in 2015.
It finally comes Saturday against No. 9 Michigan State in Columbus.
Ohio State has looked unimpressive at times against unranked teams while repeating the mantra that playing its best football is most important at the end of the season.
That moment is here for the Buckeyes (10-0, 6-0 Big Ten), who follow this game against the Spartans (9-1, 5-1) with their rivalry showdown at No.