Russ Radtke has never cared what other people thought about him.

He has proven it time and time again.

That’s why it was easy for Radtke to leave Portage for Knox without coaching a game at his new school.

The thought of taking over a program in the Duneland Athletic Conference, which has a proud past but is coming off a rocky decade, was a refreshing challenge in February when Radtke replaced Darren Rodriguez.

A little over three months later, it was either an insurmountable mountain to climb or an epic mistake.

Hiring Radtke was a regrettable debacle for Portage’s administration.

For Radtke? He’s immune to embarrassment and shame.

He slithered out the back door without any public explanation.

Radtke is a football coach with a singular purpose — to win football games.

His energy, intensity and style were unique.

The extreme practices, the maniacal sideline demeanor and the utter contempt for losing were always forgiven because Radtke’s players loved the man.

For 23 years, I have defended Radtke, mostly from the mainstream coaching fraternity. It will be hard to do that now.

Many felt Radtke didn’t do things the right way.

He ran up the scores.

At Griffith, Radtke famously used two platoons. His philosophy was he couldn’t tell his second string to back off. It was how the Panthers built their edge.

He could be brusque and dismissive after losing.

He was consumed with coaching in a way that can be hard to understand.

Once a coach confided to me that Radtke didn’t represent the profession well.

I dismissed it as professional jealousy and because Radtke was never one of them.

He wasn’t part of the backslapping fraternity of coaches that wants to be loved and respected.

Radtke cared about none of it.

All he wanted to do was coach his football team. He was in restless pursuit of the perfect game.

With a record of 368-140, Radtke is the second-winningest active coach in Indiana.

He talked about winning a state championship at Portage. He was basking in the love from co-athletic directors Fred Joseph and Mike Poynter.

Radtke said he had total control of the feeder systems.

It was a rebuilding job.

He liked the idea of returning Portage to its glory — at least for a week or two.

Sometimes, a coach turns around after he has been offered the job and returns to where he came from because he realizes he made a mistake.

See Steven Mueller, a hire at Valparaiso that lasted three weeks.

Mueller left in 2018 after being hired to replace Dave Coyle due to discomfort about his style, which included putting posters on the school walls that used military terms to motivate his players.

Mueller was a first-time head coach who made a mistake.

Radtke knew better.

What Radtke said in February seems foolish now.

We got snookered.

I bought it. Portage bought it. Radtke’s fans bought it.

A source indicated part of the reason Radtke left is because his son, Tyler, works as an administrator at Knox. Tyler was on his dad’s coaching staff at New Prairie. Knox also is closer to the farm Radtke owns in North Judson.

Russ Radtke didn’t return a text seeking comment. Only he knows.

Knox won its first sectional title last year. It will be much easier to win at Knox, a Class 3A school which played eight of its regular-season games against 1A and 2A competition last season.

The Hoosier North Athletic Conference is no DAC.

I wonder if Radtke left because he felt like his reputation would be sullied by what he viewed as an impossible turnaround job.

It doesn’t matter now.

I just hope Radtke found what he wanted.

Because he left a mess for Portage to clean up.