If you want to see a lot of downfield contact, watch U Mich's defense play, including against PSU. Lots of downfield contact on every pass play, and with the ball in the air. Harbaugh obviously exploited the B10's reluctance to call penalties on this type of play, probably recognized it on film, which helped UM's defense be so successful. In their press man coverage scheme, they man up on receivers and practically mug them all the way down the field, which frees up additional manpower to run blitz or pass rush. They did this against Penn State with great success, nearly bringing 7-8 defenders to the LOS on run downs or 5 or more pass rushers on passing downs. They simply outmanned the PSU offense at the point of attack. With PSU's OL, that means game over.