Avoid At All Costs: Michigan's defense had plenty to brag about last week as the Wolverines held Penn State a season low 283 yards, and 5.24 yards per play. But, U-M surrendered four "big" plays of 20 yards or more: a 37-yard completion covered expertly by the defense (with a perfect throw), a 44-yard run, and 25-yard and 53-yard TD passes to wide receiver KJ Hamler. 

It's the latter two that ultimately cost Michigan the game and showcased a U-M vulnerability - Don Brown's insistence to play base defense against 11 personnel (three wide receivers, one tight end and a running back) despite the fact that puts a safety in one-on-one man coverage against a slot receiver. 

That's a bad matchup for the Wolverines (it's a bad matchup for just about every team) and it was exposed by the Nittany Lions. 

So what will Brown do tonight? Will he insist on a similar coverage plan against the Irish? They don't have a Hamler but they do have athletes and sophomore WR Braden Lenzy is a dangerous playmaker that has averaged 21.8 yards per reception this season and has a 51-yard touchdown rush. 

Make no mistake, ND's coaches are smart enough to go after a Michigan weakness, daring the Wolverines to stop it. 

Take What The Weather Gives You: No one can forget Michigan's 14-10 loss to Michigan State two years ago in a second-half downpour that effectively eliminated any chance of throwing the ball successfully - U-M's John O'Korn completed 6 of 16 attempts with three interceptions and MSU's Brian Lewerke went 5 for 9 as the Spartans essentially abandoned the pass in the fourth quarter (they threw only twice in the final 15 minutes). 

Forecasts predict torrential rain for the entirety of the game. Both teams will have to play in the same conditions and neither team is particularly good on the ground -- Notre Dame ranks 41st averaging 188.5 yards per game and Michigan ranks 80th averaging 154.0 yards per game -- so it doesn't favor either team. 

Still, you'd expect both teams to be preparing a game plan reliant on the run. What will be interesting is to see how each team utilizes the read-option. Notre Dame QB Ian Book has proven to be more comfortable doing so than Michigan's Shea Patterson, but Patterson has shown greatness at it when he keeps the ball. He's been reluctant to keep this year (for reasons that have sparked plenty of theories) but has done so in some key moments. 

With the rain impacting the passing attack, perhaps, this is a game where Patterson will show greater proficiency on the read option (or perhaps we might see backup Dylan McCaffrey some, as read-option is a strength of McCaffrey's). 

Protect, Protect, Protect: The Irish rank 21st nationally in sacks per game with 3.00, led by defensive ends Julian Okwara (5.0) and Khalid Kareem (3.5). The Wolverines' offensive line pass pro has been underrated this year, largely because some blowups by the running backs have led to pressures and Patterson, himself, has created QB takedowns by panicking in the pocket. 

A week ago, however, the line was superb in limiting the pressure put on Patterson by Penn State's defense, expertly handling the Nittany Lions' blitzes off the edge. PSU's Yetur Gross-Matos (5.5 sacks) and Shake Toney (5.5) - two of the best ends in the country - had just one combined quarterback hurry and no sacks last week.

Fifth-year senior left tackle Jon Runyan Jr.,'s and redshirt freshman right tackle Jalen Mayfield's reward for keeping them at bay? They get Okwara and Kareem.

Patterson seemed to find his groove in the second half at Penn State, and was as comfortable in the pocket as we've seen all year. If he can find that comfort again, Michigan will have a chance to capitalize off the offensive momentum it established in State College.