They lost game. Coaching is a variable that decides wins or losses like anything else.If we're being objectively honest Day lost that Michigan game due to his own ego. He kept hearing Michigan and the talking heads yapping about the team that runs for the most yards wins. He basically played right into Michigans hands and didn't take advantage of his superior offensive weapons.
We see it all the time. Bama beat Georgia, then went on got sat down by Vanderbilt of all teams. Fucking roller coaster on a week to week basis.