I think the winner of this game will come down to two factors.
1. The team able to win the turnover battle
2. The team able to convert short yardage situations
------------------------------------
Neither Penn State nor Iowa has a dominating offense.
Iowa's points per game is 33.2. Penn State's PPG is 28. However, Penn State has played a tougher schedule, IMO. If that wasn't enough, Iowa has scored 75 points off of turnovers. In addition, Penn State has scored quite a few points off of turnovers themselves.
Penn State has a "not top 5" 3rd down conversion rate of 38.5%. Iowa is even worse, with a 36.2% conversion rate.
Hopefully I'll have more offensive stuff to come later.
-----------------------------------
If you dig deep into the defensive stats:
Points per game: PSU 10.8, Iowa 11.6. (In addition, 4PPG can be deducted from PSU due to garbage time scores against 3rd and 4th stringers, while no such adjustment can be made for Iowa)
However, I think Iowa has a significantly better rush defense.
Opponent Rushing yards per attempt: Iowa 2.7, PSU 3.4
PSU has faced (offensive rushing yards per attempt):
Auburn: #3
Wisconsin: #80
Indiana: #104
Ball State: #118
Villanova: N/A
Iowa has faced:
Iowa State: #9
Maryland: #46
Colorado State: #69
Kent State: #78
Indiana: #104
On the flip side, Penn State initially appears slightly better in pass defense.
Penn State is only allowing opponents 5.1 yards per pass attempt. Iowa is allowing 5.6. However, Penn State has given up nearly 250 passing yards in garbage time with their 3rd and fourth stringers. Iowa, on the other hand, has given up only 50 passing yards in garbage time. Adjusting for this means that Penn State's defense compares even more favorably to Iowa than it initially appears.
However, Penn State has faced (offensive passing yards per attempt):
Auburn: #91
Wisconsin: #100
Indiana: #109
Ball State: #116
Villanova: N/A
While Iowa has faced:
Iowa State: #34
Maryland: #48
Kent State: #93
Indiana: #109
Colorado State: #124
PSU's pass defense can only be fairly compared to Iowa when the strength of the opponent's passing games are accounted for. Once that is factored in, the teams become much, much closer.
-------------------------------------
None of this factors in turnovers. Iowa is ranked #1 in the country in takeaways. However, that average is slightly skewed by the 642 turnovers they caused against Maryland. Still, given Iowa's history, you have to assume Iowa is likely to cause at least a turnover or two. Penn State, on the other hand, has the ability to keep up with Iowa, as they rank #11 in takeaways.
Overall, these appear to be two very good defenses on par with one another.
