So, here we are at the midway point of the 2013 Big Ten football season, and I can’t help but wonder which Big Ten title contender has the most to prove in the second half. Is it Ohio State, the undefeated team that hasn’t lost since the 2012 Gator Bowl? Is it Michigan, the 5-1 team that squeaked past Akron and UConn? Is it Nebraska, the 5-1 team that lost its lone true test? Or is it someone else? I say it’s Nebraska. The Huskers, my preseason Legends Division favorite, are 5-1. But, really, what do we know about them?