We will know after Wisconsin if the D-line can stop the run as well as they rush the passer. This is the biggest difference between Ballard and Klug vs. King and Kroul. Iowa's D gave up an alarming number of rushing yards to some teams that weren't especially strong on the O-line. I think Ballard will make a big step forward this season and I am hoping Binns will as well. I think Binns' may be the best athlete on a very athletic line.
I think there is more going on than just Ballard and Klug replacing King and Kroul here.
I looked a little at the rushing defense numbers between 2008 and 2009:
2008: 94 yards/game
2009: 123 yards/game
Looks like a huge drop-off from one year to the next and it's easy to assume losing King and Kroul accounted for that drop.
But, if you look at the schedule, you'll see that 2009 went up against Michigan and Ohio State and played the one of the nation's top rushing offenses in a bowl game (versus Spurrier's Fun'n'Gun Part II in 2008).
Also in 2008's favor, you had the abberation in the Metrodome, where we got up so big on Minnesota that they couldn't run and ended with 7 yards rushing. If you take out the Michigan, OSU games from 2009 and take out the Minn game from 2008 you get:
2008: 101 yards/game
2009: 107 yards/game
I know it's convenient to leave out games that support my case, but here is my justification (which you are free to reject or accept): going into the games with mobile QBs, Norm's strategy was to #1 neutralize the QB's ability to hurt us with his feet and make plays on the edge. In order to do that it meant lessening the role of the DEs in supporting the run game up the middle.
Looking at the films of those games, Michigan and OSU ran mostly straight up the middle for most of their yards. Herron's run around the edge was originally a run up the middle that he bounced to the outside.
I personally, don't like the strategy of ceding the middle of the field and would rather have made the QB's beat us with their arms and feet.
Now, the interesting thing is, Rich Rod wasn't smart enough to figure it out and his QBs cost him the game. The Vest, who is clearly the best coach in the Big 10, outcoached Kirk once again, and scratched where it itched.
We sat there against OSU the entire time waiting and preparing for Pryor to try to beat us with his feet while Saine and Herron silently and then violently put us away.
Hopefully the coaches will have more faith in our players this year than they showed against Michigan and OSU.
But back to the original point, I dont' remember Iowa utilizing this strategy in 2008 and it proved to be a more effective defensive scheme. In my mind, that is more important than the switch from King/Kroul to Ballard/Klug.