Feng: Run game gives UM critical edge over Northwestern

Can Michigan beat Northwestern on Saturday in what seemed unlikely just a month ago -- a matchup between AP Top 25 teams?

Michigan had high hopes coming into this season with the arrival of Coach Jim Harbaugh. However, an AP rank of 18th after five games shows quick progress toward a return to UM's past greatness.

Last year, Northwestern struggled to a 5-7 record and missed a bowl game for the second straight year. A promising defense dealt with injuries while the offense stunk the entire season.

The Wildcats seem to have started fresh this season. They have already notched wins over Power Five foes Stanford and Duke, and made a 27-0 statement over Minnesota in their conference opener. This strong early-season showing has led to a rank of 13th in the AP poll.

While Northwestern and Michigan have both earned their spot in the Top 25, only one team belongs. Let's dig deeper into each team's numbers.

Two dominant defenses

Northwestern and Michigan both have excellent defenses. The markets expect a total of 35 points in this game, not far from The Power Rank's projection of 38.6. The defense should dominate a slow and ugly game.

Michigan's defense hasn't allowed a point in the last two games against BYU and Maryland. This success should continue against a Northwestern offense that hasn't improved much from last season.

At The Power Rank, I rank offense by taking yards per play and adjusting for the strength of the opposing defense. Last year, Northwestern ranked 99th of 128 teams. With a small sample of games from this season, the Wildcats rank 87th. They're maybe better than Maryland, while Michigan has the top-ranked defense.

Northwestern also has an elite defense. However, it defends the pass better than the run, which plays right into the tendencies of Harbaugh. Michigan has run on 57 percent of plays this season (this number excludes sacks that count as rushes in traditional college football statistics). In addition, UM runs the ball (53rd) better than it passes (66th).

Michigan will find it difficult to run against Northwestern's veteran defensive line. However, it will be easier than throwing, and the offense should score enough points to win the game.

Northwestern's program history

Michigan has another factor in its favor: Northwestern is on a hot streak that should regress. Let me explain.

At The Power Rank, I rank teams by taking margin of victory in games and adjusting for strength of schedule. This method assigns each team a rating, or expected margin of victory against an average FBS opponent.

The visual shows a 30-year history for Northwestern with wins and rating in the top and bottom panels, respectively.

Since Pat Fitzgerald took over as coach in 2006, the Wildcats have fluctuated near FBS average. In 2012, they won 10 games, including their first bowl win in 64 years and had the highest rating of Fitzgerald's era. In two seasons since, they have regressed back to their program average.

Compare this with the visual for Michigan.

The last eight years have been a roller coaster, but the program has a strong history before that.

As I described in a previous column, college football teams tend to persist from season to season.

Northwestern doesn't have the history or financial resources of top programs, making it difficult to sustain success.

Teams can make a big jump in rating from season to season. However, this usually requires adding an elite player like Jameis Winston or Johnny Manziel.

Preseason expectations can provide clues about teams on the rise. The preseason AP and coaches' polls are strong predictors of performance.

However, Northwestern didn't receive a vote in either preseason poll, and SB Nation called this a rebuilding year.

In all likelihood, Northwestern has played above its level early this season and will not end the season as a Top 25 team.

Prediction

My numbers give Michigan a seven-point edge, close to the market value of eight. This implies a win probability of about 70 percent.

This doesn't guarantee a Michigan win. A few key fumbles or big plays could flip this game to Northwestern. However, both past history and the matchups favor a Michigan win.

Ed Feng has a Ph.D. in chemical engineering from Stanford and runs the sports analytics site The Power Rank. Email Ed Feng here.