Joe Paterno’s dismissal Wednesday night after almost 46 years as Penn State’s head football coach — he’s leaving under a black cloud that has enveloped the campus he ruled for so long — isn’t nearly as tragic as the alleged sexual abuse of boys by Paterno’s former assistant coach Jerry Sandusky. But it is shocking and heartbreaking nonetheless.

His departure, however, is far more than “the end of an era” — the easy cliche that has been tossed around so much in the past few days. It is another step toward the extinction of a breed of football and basketball coach that for years dominated college sports, and that Paterno came to embody: the dynastic, iconic coach.

With Paterno’s firing there are now, among the 120 coaches at the top tier of college football, only two men who have worked in their current jobs for more than 20 years. Frank Beamer is in his 25th season at Virginia Tech, and Larry Blakeney is in his 21st season at Troy University. There is only one other coach — Fresno State’s Pat Hill — with 15 years on the job.

The highest level of college basketball has far more head coaching jobs — 344 as the new season begins — so the numbers there are slightly higher. But only 12 current head basketball coaches have been at the same school for 20 years or more, led by Syracuse’s Jim Boeheim, who is starting his 36th season at his alma mater.

“It’s not going to happen anymore in the future,” Boeheim said in a phone conversation the day after Paterno was fired. “Too much has changed in college athletics. The pressure to win and keep winning has grown so much that even people you might think were untouchable aren’t. I used to say that if I had two bad years, there would be some people who might want me out. Now, it’s more like one year.”

Even the most revered coaches could come under fire suddenly, Boeheim explained. “No one is immune. When I was working with Mike Krzyzewski a couple of years ago at the Olympics, he was under some pressure at Duke. If he can be under pressure, then anyone can be under pressure.”

With Paterno gone, Krzyzewski is probably the most iconic figure left in college coaching. He is entering his 32nd year at Duke and has won four national championships — tying him for second with Kentucky’s Adolph Rupp on the all-time list behind UCLA’s John Wooden, who won 10. Sometime this month, Krzyzewski will become college basketball’s all-time winningest coach when he notches his 903rd victory, surpassing his mentor, Bob Knight.

Krzyzewski’s job isn’t in jeopardy, especially since his most recent national title came in 2010. But he is keenly aware of the expectations surrounding his program.

“Sometimes I wonder if people are aware of the fact that we’ve won three straight Atlantic Coast Conference titles and that we’ve won 30 games each of the last three seasons,” he told me earlier this fall. “Two years ago, we won the national championship. Last year, we went to the round of 16 and people say, ‘Don’t worry, you’ll bounce back next year,’ as if we somehow failed. We live in a world where almost nothing is good enough.”

That sports world is filled with Internet chatter and rumors, constant rankings of recruiting classes, and angry sports-radio callers who seem to want a coach fired anytime a team loses two games in a row. That mentality was summed up by a phone call that Tubby Smith, then the basketball coach at Kentucky, received on his weekly radio show late in the 1997-98 season.

“Coach,” the caller said, “I just want you to know I haven’t given up on this team yet.”

Kentucky’s record at that moment was 25-4.

That said, the greatest demands usually come from within: from athletic directors and presidents, who are themselves under nonstop pressure to raise money from boosters and sell tickets and sponsorships. Ralph Friedgen, the football coach at Maryland, was fired last fallafter an 8-4 regular season that earned him “coach of the year” honors in the ACC. Why was Friedgen, a Maryland alum with a 10-year record of 75-50, let go? Easy: The team wasn’t selling enough tickets, and donations from boosters had flagged because the Terrapins were consistently good but never great.

Boeheim insists that the stratospheric salaries commanded by successful head coaches have little to do with the shorter tenures. And yet, there is evidence to the contrary. Rick Pitino, now the basketball coach at Louisville, has won big everywhere he has coached at the college level. He has led four college squads (Boston University, Providence, Kentucky and Louisville) and two NBA teams (the New York Knicks and the Boston Celtics).

After winning a national championship at Kentucky and going to back-to-back national title games, Pitino was as revered as any figure in Kentucky since Rupp. Yet he left to coach the Celtics because he was offered $10 million a year and absolute power to make all personnel decisions. He failed miserably in Boston and took refuge at Louisville — making him a pariah among the Kentucky fans who once worshipped him. He is extremely well compensated (about $3 million a year) for dealing with that anger.

Other coaches keep moving so the posse won’t catch up with them. John Calipari has coached at Massachusetts, Memphis and Kentucky — with an unsuccessful but lucrative NBA stop between the first two schools. He took both Massachusetts and Memphis to the Final Four, but you won’t find any trace of those accomplishments in the NCAA history books; the schools were “vacated” from those tournaments because of rules violations, their victories simply erased.

That didn’t matter much to Kentucky, which is paying Calipari $4 million a year to restore the program to its former glory. The Wildcats reached the Final Four last season. If Calipari wins a national championship this season, he may be offered a contract for life. He’ll probably take it. That might mean he’d stay another five years.

Getting caught cheating might get you fired. Ohio State football coach Jim Tressel was finally forced out last spring in spite of his brilliant record (including one national championship and seven Big Ten conference titles) because his convoluted story — not to mention cover-up — about rules violations kept unraveling. But Tressel will coach again if he wants to. Someone will always hire a proven winner, regardless of any skeletons in his closet.

Contrary to what some people think, Duke did play basketball before Krzyzewski’s arrival in 1980. In fact, Bill Foster, his predecessor, took Duke to the national championship game in 1978. Two years later, he fled for the head coaching job at South Carolina after “only” taking Duke to the round of eight in the NCAA tournament that season.

“One thing I’ve learned in coaching is this,” he said back then. “Your friends come and go. Your enemies accumulate.”

Paterno was the exception to all of that. He had chances to coach in the National Football League and said no. He could have made more money at other places and said no. And yet, when his program slipped several years ago — four losing seasons in five from 2000 through 2004 — Penn State President Graham Spanier (who also lost his job Wednesday) went to the coach’s house to suggest that Paterno, then 77, think about retiring.

Paterno threw him out and went 11-1 the next year.

He wasn’t the first coach to have that kind of power, but he may have been the last. And he was almost certainly the last one who could have four losing seasons in five and keep his job.

Of course, losing didn’t do in the man known to everyone at Penn State as Joe Pa. More than anything, it was the belief within the school, right up to the president’s office, that Paterno and the football program were bigger than anything — even an ongoing tragedy involving young boys. No coach on a college campus, no matter how many games he wins or how good a man he appears to be, should be put on that sort of pedestal. The corrupting influence of power is too great.

There won’t be anyone like Paterno ever again. There won’t be many like Boeheim, Krzyzewski and Beamer, either. Those days may not be over, but they are clearly coming to an end. And as sad as Paterno’s fall from grace may be, that end might not be a bad thing

John Feinstein is a sportswriter and Washington Post contributor. His 28th book, “One on One: Behind the Scenes With the Greats in the Game,” will be published this month.He will host an online chat about this story on Monday at 11 a.m. Submit your questions before or during the discussion.

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