Part of an erratic series. Check the comments for potential corrections from gsimmons and others who are actual coaches.
Notre Dame didn't have a ton of success running the ball against Michigan, but their performance against Michigan State—2.0 YPC for the running backs—indicates they suck and that any amount of success is disturbing.
Notre Dame's run strategy last Saturday was to double the hell out of the defensive tackles and exploit Michigan's crappy linebacking. Time and again ND would leave Michigan linebackers totally unblocked and still pick up plenty of yards; they did this mostly by crushing Johnny Thompson with their fullback. An example follows.
It's second an nine on ND's first drive of the third quarter; they come out in an offset I and Michigan has their base set on the field.
The play is pure caveman: an iso up the gut. Will Johnson is doubled; this one of the rare times that Taylor doesn't get the double himself. Johnson's holds up decently on the initial play and Jamison isn't upfield so the hole Thompson has to deal with is manageable.
Thompson meets the fullback and makes a critical mistake: he lets the FB get outside of him, losing leverage on the ball and opening up a hole outside. There's no one outside of him: he's the outside linebacker.
Meanwhile, Johnson has slipped and is going to the ground; Ezeh has to watch a cutback lane opened up and is hesitant; he still needs to read the RB's cut faster than he does. (It wouldn't have mattered much because of Thompson's failure to get to the outside shoulder of his blocker.)
Thompson is now getting shoved backwards by the FB, and Johnson is finished getting wiped out. Note that Taylor has beaten his blocker and slid down the line; if Thompson had done his job and funneled the tailback inside there's a good chance he's making a tackle right now.
Thompson did not do his job and is now three yards downfield; Hughes takes it up into a sizable hole, gaining seven. Notre Dame would run the exact same play on second and three, gaining thirteen as Thompson repeats the performance encapsulated here.
This play highlighted a number of themes from the day: Taylor crushed single blocking whenever Notre Dame provided it, which was rarely. Johnson did okay against a wide array of double teams but not great. Thompson was owned by the fullback, and Ezeh was hesitant.