There’s no college football program quite like that NFL factory based in Tuscaloosa, Alabama. Those who make it out of that cutthroat environment have an uncommon bond.

There seems to be an unspoken code that lasts into their pro careers, which certainly has been the case for Bears safeties Eddie Jackson and Ha Ha Clinton-Dix. It doesn’t matter that they’re veterans and multimillionaires. There’s a higher standard to which they hold each other, adamant that they won’t disappoint the place that forged them.

“We know the program we came from and what the expectations are for us,” Clinton-Dix said. “The way we pressure each other about getting better . . . definitely comes from that.”

The best of the best head for the ‘‘Hunger Games’’-style competition under Alabama coach Nick Saban. Jackson wasn’t promised anything but a chance to vie for snaps at cornerback. Prospects go with something to prove and find out pretty quickly if they’re good enough.

“Hell, yeah,” Clinton-Dix said. “You either survive or you get left.”

Saban tested Jackson immediately by making him cover Amari Cooper, who put up a 1,000-yard season as a true freshman the year before.

Jackson will see him again Thursday, when the Bears host the Cowboys, and Cooper remains incredibly dangerous. He has 971 yards and seven touchdowns, both fifth in the NFL, as he closes in on 1,000 yards for the fourth time in five seasons.

There’s a healthy respect both ways.

“I already know what [Jackson and Clinton-Dix] are all about,” Cooper said.

Jackson’s first encounter with him was a disaster. Cooper destroyed him repeatedly until Jackson finally tried to surrender. He turned around and pleaded for mercy from a man not exactly known for that quality.

“Don’t look back at me, Eddie,” Saban yelled. “I’m not gonna take him off your [butt].”

Cooper chimed in with, “Mess with me, and I’m gonna make you live.”

That’s the PG-rated version, as Jackson recalls.

Pro athletes rarely tell stories like that. Even years later, good luck getting them to admit that anyone ever dominated them in any setting. There’s too much pride to concede that they ran up against someone superior. Jackson probably wouldn’t acknowledge it about anyone who didn’t go to ’Bama.

Anyway, it was humiliating and exasperating. But Jackson embraced it and took the pounding until he finally rose to Cooper’s level during spring practices after his freshman season.

“That’s when everything came, and I was like, ‘All right, I got him,’ ” Jackson said. “We’d go do one-on-ones, and now it was going tit for tat. It used to be Amari, Amari, Amari. Now it’s Amari, Eddie, Amari, Eddie. He helped me build and get me polished to be able to cover.

“Coach Saban put me in that fire early. He knew going up against Coop was going to bring the best out of me, and it did. Going up against a guy like that every day in practice, man, it’s a challenge. But in the end, it all pays off.”

Since he went to Alabama, Jackson faces his college buddies all the time. All but four teams — the Rams, Saints, 49ers and Eagles — had a Crimson Tide player on their roster to start the season.

Jackson likes to trade jerseys with them and already has collected them from Buccaneers tight end O.J. Howard, Lions defensive tackle A’Shawn Robinson, Redskins linebacker Reuben Foster and Ravens cornerback Marlon Humphrey. He’s looking to add Cooper’s.

But before they get to that, they’ll meet on the field. While they won’t be matched up directly now that Jackson plays safety, they’re sure to clash on a few plays, and it’ll be as fierce as their battles in Tuscaloosa.

“It’s a little chitter-chatter here and there, but it’s all love at the end of the game,” Jackson said. “You really get to see how it feels being on the other side and seeing how opponents felt in college.”