Not only has the Notre Dame Fighting Irish football team started 4-0 after Saturday's 13-6 win over Michigan, the team has done it with a dominant defense. Notre Dame blog One Foot Down discussed how impressive that defensive effort has been:

The Irish have finished the first quarter of their season undefeated. They've allowed 36 total points over four games in September--that's nine a game if you're using science, and I am. And it ain't like the Irish beat up on Florida International or some other rent-a-win school with name that sounds like some two-bit regional airport. The Irish held Navy and three B1G question mark opponents to an average of 9 points. This is impressive even though the B1G is not.

That defensive effort has been needed as the Irish have averaged just 17 points per game in three games since scoring 50 against Navy in the season opener. Notre Dame hasn't allowed a touchdown in its last two wins, over Michigan and Michigan State.

Be sure to stay with this StoryStream for full Michigan/Notre Dame coverage, and head over to One Foot Down for more on the Irish and check out Maize N Brew for more Michigan football news. Visit SB Nation's college football hub for more news from around the nation.