1. This game shows us why strength of schedule matters. During the 24-game winning streak, Ohio State's opponents had a combined record of 138-159 (.465 winning percentage), and only three of the opponents were ranked: 2012 Nebraska (#25 AP, #23 BCS); 2012 Michigan (#24 AP, unranked BCS); and 2013 Wisconsin (#21 AP, #21 BCS). This team needed to be tested by good competition, so that it could be prepared for a game like tonight's. There's a reason that the SEC wins championships, and that's because they have to play championship-level football more than once a year.
2. In the last four games, Braxton Miller was 38 for 82 passing (.463 completion percentage) for 544 yards (136 yards per game). The running game is great, but the pass offense has to provide some kind of threat or else the opposing defense will adjust and shut down the run, just like MSU did for the final twenty minutes of the game.
3. Defense wins championships. This is not a championship defense. I don't care what scheme the coaches employ, guys like Curtis Grant, Josh Perry, Pitt Brown, C.J. Barnett, and Tyvis Powell simply cannot play at a championship level (and I also have my doubts about Doran Grant, after seeing MSU's less-than-stellar receivers beat him consistently). Bosa, Shazier, and Roby all had great games (and Washington was solid), but a few guys can't carry an entire defense.
4. Michigan State has only 14 wins against Ohio State (versus 28 losses), but four of those wins ruined perfect seasons for the Buckeyes (1972, 1974, 1998, and 2013).