CHICAGO — In the olden days, coaching rivalries could be pretty serious.

Bob Knight and Gene Keady are best buds now that they’re retired, but there was no love lost when they coached against each other for Indiana and Purdue.

And that wasn’t even Knight’s fiercest rivalry.

Former Illinois coach Lou Henson was a frequent Knight target. Knight thought Henson was a cheater. The gentlemanly and generally hospitable Henson felt Knight was an uncouth bully. The disdain was mutual and deep. And, of course, highly public.

And nobody’s got anything on John Chaney and John Calipari. Chaney, the legendary Temple coach, once barged into a Calipari press conference threatening to kill him.

Maybe not the first coach to think that about Coach Cal, but very much the only one to speak it out loud. In public. With cameras rolling.

And then we have Matt Painter and Micah Shrewsberry.

Wherever you place those old-school rivalries on the spectrum, Painter and Shrewsberry are on the opposite end.

Actually, they do a full lap around the spectrum, then go to the opposite end another revolution over. This is a pure lovefest.

Part of that is just the nature of their previous relationship. Shrewsberry is Painter’s protege, a former Purdue assistant who is growing the Painter coaching tree. (Though as Knight proved with Mike Kryzyzewksi, not even that guarantees a good relationship.)

“We root for Micah,” Painter said. “Obviously we don’t when he plays Purdue. He’s grown our program. He made us better. We learned a lot from him from his experience with Brad Stevens with Butler and the Celtics.”

That sentiment is echoed by Big Ten player of the year Zach Edey.

“I want to see ‘Shrews’ win unless it’s against us,” Edey said. “He helped me so much as a freshman.”

Shrewsberry has the same kind of aw, shucks mentality going the other way.

“I don’t know about that. They’re just being nice,” Shrewsberry said. “That’s his program. He’s been doing great things for so long. Like, I just wanted to be a small part of it.”

Are these guys even gonna play a game, or gather at center court for a drum circle?

Shrewsberry assures us that things will change as soon as the ball is tipped.

“I’ll see him in the hallway, and we’ll joke and we’ll laugh and we’ll shake hands when they announce our names, and then tooth and nail we’re going to fight each other,” he said. “We both love to win. We both hate to lose. So in that moment, that’s all we’re focused on.”

Shrewsberry is willing to accept a forfeit, however.

“I would love it if he felt a different way and was like, ‘Hey, why don’t you guys go ahead and win? We’re not going to show up tomorrow,'” Shrewsberry joked.

Presuming Purdue does show up, we have to make a prediction.

Predicting Sunday’s Big Ten championship game

No. 1 Purdue vs. No. 10 Penn State

The Nittany Lions are the lowest seed to reach the Big Ten Tournament final since No. 10 Illinois in 2008. The Illini — who opened that tourney with a win over Penn State — ran out of steam in their 4th game in 4 days. Top-seeded Wisconsin snuffed out their hopes of an NCAA Tournament bid.

Unlike that Illinois team, Penn State is already securely in the field. The Nittany Lions are simply playing for history. The 1991 Atlantic 10 tournament is the program’s lone conference title.

“We’ve been talking about playing in the Big Ten championship for a long time. I’m so ecstatic I can’t even put it into words,” said senior forward Myles Dread. “[Winning] would be lovely. We want to do it for this team. We worked so hard in preseason workouts. Not for the season or the coaches, but for each other.

“To have something to show for it would mean the world.”

Penn State isn’t alone in chasing history. Purdue has plenty of regular-season hardware, but is looking for its first Big Ten Tournament title since 2009.

Prediction: Purdue by 13.

Let the record show that I am a Penn State basketball enthusiast. Maybe even a Micah Shrewsberry fanboy.

Before this tournament even began, I labeled Penn State as the most likely champion of the teams that didn’t get a double-bye into the quarterfinals. But that prediction came with a bit of foreshadowing: “Purdue is a troublesome matchup for Penn State, but the Nittany Lions would have a shot against any other potential championship game opponent.”

Well, here we are. This isn’t any other potential opponent. This is Purdue. And the Nittany Lions don’t have the personnel to prevent Zach Edey from having a field day. The Boilermakers won the previous 2 meetings by a combined 33 points.

At least Shrewsberry won’t have any issue giving Painter a hug when it’s over.