Looking at play-by-play for the first half shows this about rushing vs passing:
1. 1st and 2nd down rushing went well against Washington State from the start, was mixed against Kansas, was poor against Michigan State (except for one big run) and was totally dismal against Penn State.
2. Here are the 1st down rushing yardages against Kansas in the first half: 2, 2, 1, 2, 3, 5, 7, 7, 4. Here are 2nd down yardages: 0, 2, 35, -2, 2, 6, -1, 31. I didn't see the game but the longer runs in the 2nd quarter suggest they were finding or making holes for the backs to pop off longer runs but they were pretty much running into brick walls for the 1st quarter.
3. Against Penn State the rushing game failed almost entirely on 1st down and the offense switched to passing on 2nd down early and often. The results were mostly not good.
4. Against Michigan State the rushing game did not work well early--until Paul James 72 yard rush during the 4th possession. Prior to that rushing plays on 1st and 2nd down got yardage of -1, 3, -1, 2. After the 39 yard TD pass to Carroo the next two rushing plays got 12 and 9 yards. Coincidence? Probably not.
5. Right now I think it's hard to say if the offense is really getting enough yards rushing on 1st and 2nd down or if it's going to be a tough slog going forward. It did well enough against two poor opponents but had mixed results against Big Ten opponents. Against Michigan State it was saved by a couple of big plays. Will it be able to reproduce that against Ohio State, Michigan, Wisconsin, Nebraska?