In fact in their last 3 games they allowed 249. 300 and 389 yds on the ground. BYU should have as full stable of RBs. The hope is we comfortably run our way to a win. They are pretty bad against the pass as well allowing 258 YPG as well. So it may be dealer's choice in how Arod wants to attack their D because they are weak at multiple levels.
Their strength on Offense is passing yds where they avg 299. Most of those yds came from Alan Bouman who has apparently been benched in favor of Soph QB Garrett Rengel. He's had limited action but looked terrible against Utah. He did close out a TD drive during garbage time in their blowout loss to WVU. Not sure what his strengths and weaknesses are because he hasn't played much over the last 3 yrs, but doesn't appear to have significant run stats either. OSU is looking for a spark, but not sure what Rangel does to improve their chances to win.
With all this said, I'm still worried about OSU. They should absolutely lose this game on paper, but I've experienced many BYU losses on the field that were wins on paper. However, these data points above do help me work out a path to victory in my head.