If Iowa hopes to upset No. 3 Ohio State on Saturday afternoon in Columbus, it would be wise for the Hawkeyes to get off to a good start. While the Buckeyes (4-0, 1-0 Big Ten) have outscored opponents by an average of 42 points (48.

8 to 6.8), they have been more vulnerable in the first half before making defensive adjustments. The Buckeyes have a 91-3 scoring advantage after halftime after a combined 104-24 in the first two quarters.

Their yards allowed are just as dramatic. They gave up 186 in the first half to Marshall on Sept. 21 and 203 last Saturday in a 38-7 victory over Michigan State followed by second-half totals of 61 and 60, respectively.

"We want to get stops. We want to force three-and-outs," Ohio State coach Ryan Day said. "We're going to deal with the same thing this week.

Those guys (Iowa) have made improvements in a lot of areas on offense, and I think they're playing really well, so it's another challenge for our defense." Iowa (3-1, 1-0) likely won't be able to match the Buckeyes' high-powered offense but will try to control the ball and take the crowd out of the game. One of the keys will be Hamilton, Ohio native Kaleb Johnson.

In a 31-14 win against Minnesota on Sept. 21, he rushed for a career-high 206 yards on a 9.8 yards-per-carry average with three touchdowns for his fourth straight 100-plus-yard game.

He is No. 2 nationally with 685 yards. Iowa coach Kirk Ferentz knows the Buckeyes will be ready for Johnson.

"It's going to be a tough challenge," Feren.