The knock on the door of room 108 in Steeb Hall sounded no more ominous than usual. The person doing the knocking, however, was more threatening than an alligator let loose in the bathtub.

Kelvin Bell and his roommate, Kevin Richardson, were watching TV on the 19-inch, black-and-white set when the knock came. The Ohio State freshmen teammates figured a dorm friend wanted in. They figured wrong.

“I open the door and there’s coach Saban,” Bell said this week, recalling the moment in 1981 when his 18-year-old life passed before his eyes  “I had missed a couple of classes and …”

Uh-oh.

Saban liked Bell, having formed a strong relationship with him while helping recruit the safety out of Richmond, Virginia during his second season coaching the Buckeyes secondary. (Don’t tell the NCAA, but it may have been Saban – ahem – who supplied the TV.) But liking does not preclude a coach from confronting.

Saban blew past Bell, unplugged the TV and carried it from the room as he huffed, “Hey, you missed classes. You must be watching too much TV.”

Lesson learned.

“I wanted the TV back, so after that it was ‘I’m getting my ass to class,’ ” Bell said, chuckling. “It was like something your parent would do.”

Ray Ellis laughed at the TV story. The former Ohio State cornerback spent his senior year in 1980 with Saban. He knew how his position coach operated.

“Gravitas is the word I would use to describe Nick Saban,” Ellis said. “He was a no-nonsense coach. I doubt any of us ever saw him smile or laugh about anything.”

Pete Carroll was the opposite. Ellis played his junior season under Carroll, who coached the Ohio State secondary in 1979 before becoming defensive coordinator at North Carolina State.

“Both bring a ton of energy, but in different ways,” Ellis said, comparing Saban and Carroll. “Pete brings that animated energy while Nick brings that stern type of energy. Pete will maybe body bump a player, maybe run down and celebrate a touchdown with a player. Nick was just the opposite. He was that teacher who is a great teacher, but everyone in high school knows that is a tough class with a tough teacher.”

Ellis would not, could not, choose between the two. Both left a lasting positive impression on the former college and NFL player.

“They both wanted you to be great,” he said. “They knew you had potential and wanted to be sure they got 100% of your talent out of you, and so they pushed you to that edge.”

Ellis attributes his college and pro success – he played seven seasons with the Cleveland Browns and Philadelphia Eagles after being the next-to-last player drafted in 1981 – specifically to Carroll and Saban.

“Without a doubt, it was due to Pete Carroll and Nick Saban providing me with the best teaching instruction one could ever expect,” Ellis said. “I listened to and followed the direction of every word they spoke, and for me, it certainly paid off, both on the field and off. I hope they both find joy and success in their lives in whatever they choose to do for the remainder.”

Saban and Carroll, both 72, are finished coaching. Saban is retiring after 17 seasons at Alabama, where he won six national championships, as well as one at LSU. Carroll was fired by the Seattle Seahawks last week after 14 seasons. Moving into an advisory role with the team, he won one Super Bowl and took the Seahawks to another.

Bill Belichick is also out at New England after 24 seasons and six Super Bowl wins, but plans to keep coaching.

They say it is never smart for a coach to immediately follow a legend. Better to be the coach who follows the coach who followed the legend. But in a triangle of connection, Saban, Carroll and Belichick all thrived while playing some part in following or being followed by one or the other. Saban followed Carroll at Ohio State before getting fired by Earle Bruce after two seasons, then Saban followed Carroll as the king of college football.

Carroll was considered the top college coach when he was at Southern California (2001-2009) before Saban took over that mantle after arriving at Bama in 2007. Belichick replaced Carroll in New England, where Pete coached three seasons (1997-99) before getting fired and heading to USC.

The three men are intertwined not only professionally but also in the collective consciousness of all who count time in decades. Saban, Carroll and Belichick are yesterday’s Osborne, Bowden and Shula, who were successors to Leahy, Wilkinson and Lombardi, and so on down the line.

“Belichick, Saban and Carroll – our era of football is fading fast,” Bell said, wistfully. “I just hit 60 in September and I just sent that same message to my close network of former teammates. It hits you.”

As a kind of congratulatory send-off, it is worth digging into what made the three legends so successful.

Carroll first:

“Pete is the kind of guy who is in fifth gear every minute of the experience,” Ellis said. “Doesn’t slow down for anything. That was what we noticed right away (in 1979). He had more energy than we did.”

Energy is great, but Carroll also had the ability to channel it to players, who fed off it. Ellis recalled how Carroll demanded – yes, he could be as demanding as Saban or Belichick – that his defensive backs never give up on a play.

“We’d be watching film and at the end of every play, Pete would say, ‘Every defensive back should be in that snapshot. I want you running to the ball.’ ”

Belichick:

Former Ohio State linebacker Bobby Carpenter spent one NFL season playing for Belichick. His takeaway?

“What separated Bill, which he probably got a lot of from Bill Parcells, is he is always looking at the game holistically; how to win the game. Bill looked at every situation with victory as the goal, how best to win the game. And he built gameplans around that, not ‘We want to score 45 points,’ or whatever. And we were ultra-prepared. There was no situation we didn’t go over.”

Belichick also emphasized drafting and signing players based on their intelligence.

“The locker room was one of the smartest I’d been around,” Carpenter said. “There was such diversity of geography and everything else. He wanted smart guys who really loved the game, because if not, the game is too tough to play and the monotony will wear you down.”

Saban:

Don’t let looks fool you. At least not totally. A coach doesn’t win as many games and titles without having some ability to win over the hearts of players.

Saban earned respect with his my-way-or-highway approach but gained loyalty through his interactions with players behind the scenes.

Bell will never forget how Saban and his wife (Miss Terry) visited him in the hospital after Bell suffered a cut on his foot when OSU trainer Billy Hill accidentally sliced him while attempting to remove a callus.

“I was homesick and was thinking my shot to play was not coming now, and (the Sabans) treated me like their son,” Bell said. “I was in the Ohio State Hospital a couple days with a bad infection and they were bringing me (note paper) to write my high school girlfriend.”

Ellis shared a similar story about how after getting struck by lightning in a phone booth – wild, right? – the Sabans visited him in the hospital.

“It troubled me at first, the fact that I was so happy to see them even though I was somebody else’s son, but then I embraced it,” Ellis said. “Nick was kind of a father figure to me. And Pete was like a big brother.”

Carpenter never played for Saban but bumped into him once in Miami and asked if he was as much of a “hard ass” as everyone says.

“He says, ‘I’m way harder on coaches than players,’ ” Carpenter said. ‘My job is to make sure they’re getting the best out of you.’”

Which by association meant Saban got the most of them, too. So did Belichick and Carroll. Three amigos – two of whom are riding into the sunset. Adios and happy trails. They’ve earned it.

roller@dispatch.com

@rollerCD

This article originally appeared on The Columbus Dispatch: Ohio State defenders recall Bill Belichick, Nick Saban, Pete Carroll