While you could argue in favor of many defensive philosophies, a run-stopping defensive philosophy tops the list every day of the week. Sure, spread offenses have changed the game – I see more nickel defense these days than I do base defense – but regardless of the amount of DB's on the field, you need to stop the run to win Big Ten Championships.
Stopping the run is the ultimate fundamental of defensive football. If defense is about toughness, what is tougher than stuffing the running game? When an offensive line owns the line of scrimmage and a tailback runs downhill through massive seams in a defense while delivering blows to linebackers and safeties on their heels, it is embarrassing for the defense. That offense is more physical than you. That offense is mentally and physically tougher and you have been dominated.
On the flip side, when a quarterback throws a deep pass to a streaking receiver and they score a touchdown, you haven't necessarily been beat up. The scoring damage is the same. The tangible result is the same. However, the morale is different. A team running down your throat will demoralize a defensive unit. Defensive player's heads will be hanging. There won't be much eye contact in the huddle. You are taking an absolute beating at that point. Football is not fun when an offense punishes you with a running game.
The effects of run vs. pass are huge. The clock is drained when an offense runs the ball (meaning a fresh, fast defense will take the field for them eventually). The ball is better protected for the offense when running. When throwing, you have a quarterback exposed to big hits (and big fumbles). You also have a ball in the air, which can be thrown incomplete or bobbled for a defense to pick off. The old saying is true: "When you throw the ball, two of the three things that can happen are bad."
My point is not that OSU's offense should only run the ball. In fact, you would probably be hard-pressed to find someone that preaches balance on offense more than me. The point is that OSU's defense needs to stop the run. That opposing offense can't be balanced when they can't run the ball. If you beat OSU with a finesse game, Coach Heacock might sleep at night. If you beat OSU by physically intimidating their defensive line and linebackers with the run, Coach Heacock will be tossing and turning. I can assure you, his number one priority will be run defense. You can't win in our world unless you stop the run.