Because it runs a pro-style offense, Iowa doesn’t feature many gadget plays or spread sets or quick reads.

Instead, the Hawkeyes thrive on old-school football, predicated on protecting the quarterback, opening holes in the running game, and controlling the clock.

Once an NFL offensive-line coach, Kirk Ferentz knows no other way.

The last two seasons, the 12-year head coach’s plan has worked beautifully. Twenty wins, the program’s first BCS bowl victory, and a hyped 2010 season upcoming.

But in that wave of success, the Hawkeyes have seen six longtime offensive-line starters graduate or depart early for the NFL — Rob Bruggeman, Seth Olsen, Bryan Bulaga, Dace Richardson, Kyle Calloway, and Rafael Eubanks.

Julian Vandervelde has been the only constant over this three-year period. A senior, Vandervelde, who will likely play left guard in next season, started 15 combined games as a freshman and sophomore, with nine more coming last season.

“He brings a lot more experience there,” offensive coordinator Ken O’Keefe said.

Though he’s a sophomore, Riley Reiff has 11 starts in his career.

He displayed his versatility last season, playing three different positions — left tackle, left guard, and right tackle. In the fall, Reiff will play left tackle, a position with which he grew comfortable last year in the three-game absence of Bulaga — a likely top-10 pick in tonight’s NFL draft.

“He has all the tools,” senior quarterback Ricky Stanzi said. “We have a lot of faith in him, and I know he’ll answer because he’s a guy who’s very physical, he works very hard — and those are the two main things we need on our offensive line.”

Beyond Reiff and Vandervelde, though, experience along the line becomes an issue. Only junior Adam Gettis has started for the Hawkeyes, and that was in the 2009 season-opener against Northern Iowa. Richardson and Reiff took over the spot from there.

The Frankfort, Ill., native is “working probably better than he ever has,” O’Keefe said. At this point, Gettis (right guard) and junior Markus Zusevics (right tackle) seem to have their starting spots solidified.

O’Keefe went as far as to say Zusevics has been the Hawkeyes’ most-improved player up front.

“He’s a guy who has been in the shadows a little bit because of Calloway and Bulaga,” the offensive coordinator said. “But right now, he appears to be really hungry, and he has paid attention to what was going on the last few years, and he has had a very good spring.”

At center, things get interesting.

Calling it a “dead-heat,” Ferentz said his son, sophomore James Ferentz, and senior Josh Koeppel are competing for the final spot along the line. James Ferentz played nearly the entire spring game at center, but that was only because Koeppel injured his ankle and sat out the final week of spring ball, which Kirk Ferentz said “really impeded his progress.”

In his young career, James Ferentz has only seen action in one game; Koeppel has gotten on the field in 14 contests but never started.

“We’re young. We’re going to make some mistakes, but every day, we got a little bit better,” Reiff said following the spring scrimmage.

Stanzi, for one, isn’t too worried about the Hawkeyes’ youth up front. The quarterback said the line showed a lot of progress in passing-specific drills, where the defense knows the quarterback is going throw, making the ability to protect more difficult.

Senior fullback Brett Morse said Iowa’s experienced offense can only help the line’s progression through camp and the start of the season.

“We’ve got a lot of seniors, and we’ve been playing together for a long time with guys like [Stanzi] — it’s his third year starting,” Morse said. “He’s a great leader out there. And the guys who are new, they’ve still played a little bit, and we’re confident in what they can do.”