Jim Harbaugh recently revealed one of his keys for the B1G matchup with Michigan State in Week 9.

Knowing rivalry games can get especially chippy, Harbaugh stressed the importance of his team not committing penalties, especially emotional ones. Harbaugh said that “the guy who retaliates gets penalized.”

The Wolverines and Spartans are both among the lesser-penalized teams in the nation. The Wolverines have been called for 33 penalties, while the Spartans have 39.

There is no love lost between the rivals. For example, a notable incident before the 2018 matchup had both sides heated before kickoff.

The Spartans have been victorious over their rivals in back-to-back seasons. The Wolverines are seeking to end that streak and remain perfect on the season.