Forty coaches on Big Ten football staffs weren’t at their current schools last year.

Head coaching changes at Illinois, Ohio State and Penn State account for most of them. Defending conference-champion Wisconsin lost a whopping six assistants. Three followed former Badgers offensive coordinator Paul Chryst to Pittsburgh when Chryst became the Panthers’ head coach last winter.

Those things happen a lot in college football. Coaches on staffs that don’t win get fired. Those associated with winners get other opportunities.

Greg Davis and his quarterback, James Vandenberg (Brian Ray/The Gazette-KCRG)

But Iowa was where coaches could buy instead of rent, add a swimming pool in the backyard if they wanted. At Iowa, stability and continuity are regarded as sacred treasures. But eventually, every deck gets shuffled. Iowa’s was shuffled this off-season in a significant way, and we start seeing the results Saturday afternoon when the Hawkeyes play Northern Illinois at Soldier Field.

Iowa has three new assistants, and two new coordinators after Ken O’Keefe and Norm Parker had been in those positions for all of Kirk Ferentz’s first 13 years as the Hawkeyes’ head coach.

Plus, four incumbent assistants are in different roles than they were a year ago. One, Reese Morgan, has shifted has gone from being the offensive line coach to guiding the defensive line. That’s change.

What the heck happened? Nothing abnormal at all. Parker retired, to no great surprise. O’Keefe got a job with the Miami Dolphins. D-line coach Rick Kaczenski moved to Nebraska’s staff.

But since all of that occurred after last November, it’s a veritable tsunami of change in Iowa City. And it probably couldn’t have come at a more opportune time. Because this program had gotten stale.

Yet, has there been actual, tangible change in Ferentz’s program? We won’t have a clear idea until we see a few ballgames, maybe the entire season. But a leading indicator that Ferentz had truly opened his mind to giving his program a 14th-year tuneup came in this comment he made Tuesday:

“We have made tweaks along the way. Probably more this year than any year … it’s like our defensive play, it’s subtle. How much you will notice, I don’t know. But it’s fair to say we have adjusted and tweaked more than we have in 13-plus years.”

If Ferentz is admitting there have been adjustments and tweaks, then there have been adjustments and tweaks.

Just how much adjusting has been done, and how effectively, are mysteries we’ve waited to see unfold since Phil Parker was promoted to defensive coordinator and Greg Davis was hired as the offensive coordinator in February.

Will this be a more pressing, aggressive defense under Phil Parker? Will Davis use Iowa’s receivers and backs in ways they haven’t been utilized, will the tempo of the offense be faster and less predictable than those of Iowa’s past?

Will we no longer hear opposing defensive players say “We knew what they were going to do” in postgame interviews?

“Yet,” Ferentz said, “(we’re) still trying to be mindful of what the fundamentals are and what we feel is important to be successful. We haven’t strayed too far from the things we value.”

Of course.

Phil Parker listens to Kirk Ferentz (Liz Martin/The Gazette-KCRG)

“It’s definitely continuation,” said Iowa red-shirt freshman offensive guard Austin Blythe, who be a starter Saturday in his college debut. “Nothing really has changed. Just a new enthusiasm that’s been brought in by the changes, I would say.

“The new-found enthusiasm is what’s a little different. … Coach Davis, he’s been great, through the spring and training camp. He’s right up there with us if we score a touchdown, always congratulating. He’s definitely an encouraging coach.”

A fresh coat of paint. Some new blood to get the old blood pumping a little harder.

It can be something as seemingly innocuous as new offensive line coach Brian Ferentz using #BulliesoftheBigTen as catchphrase to his players, as well as his Twitter hashtag.

“I think he’s bringing it back from when he used to play here,” Blythe said. “He just wants us to gou there and be the most-physical team, be the most-dominant team — the most-dominant offensive line, rather.

“He wants us to incorporate that into the team and have everybody play as physically as we can, and things will be good.”

That’s still the constant, the Kirk Ferentz mantra, forged in the iron-pumping domain of strength coach Chris Doyle. They are 14-year guys.