COLLEGE STATION, Texas -- For nearly 30 years, John Chavis had only two football addresses, which in the coaching world is about as rare as taking an extended vacation in the fall.

He coached for 21 years at his alma mater, Tennessee, and spent the last six at LSU. Along the way, he was showered with other opportunities, both college and pro, but his loyalty always got the best of him and he never could bring himself to leave. So when he upped and left LSU for Texas A&M following the Tigers’ Music City Bowl loss to Notre Dame last season, it wasn’t written off as yet another coach bolting for yet another job.

Nope, this was one of the most respected defensive coordinators in the college game leaving for a job in the same division and saying very little, if anything, on his way out.

And that’s when it got testy.

LSU athletic director Joe Alleva claimed Chavis owed LSU $400,000 for breaking his contract. Chavis responded by filing suit and saying he didn’t owe the buyout because he gave LSU proper notice before officially starting his job at Texas A&M. LSU countersued, and the two sides have since amended their lawsuits against each other. Of note, Chavis says LSU owes him more than $200,000 for incentives and unpaid vacation and claims LSU amended his contract illegally in 2012, which voided it.

Ultimately, the courts will decide who owes whom. But for Chavis, who refuses to go into specifics about where it all soured at LSU, he couldn’t be happier about his decision to join Kevin Sumlin at Texas A&M and do his part to help bring the Aggies a championship.

“There were some factors that I can’t talk about and I’m not going to talk about,” Chavis told ESPN.com last week as the Aggies wrapped up spring practice. “But it came to a point that there was no doubt in my mind that Texas A&M was the best thing for me and the right thing, 100 percent.”

What Chavis will say is that his exit from LSU had nothing to do with his relationship with LSU coach Les Miles, nor did it have anything to do with money or any of the Tigers’ struggles on offense.

“You hear some of the things being said about why I left and my character being attacked, that it was about money or the offense there,” Chavis said. “That’s disappointing because it was never, ever about any of those issues. And let me tell you this: Coach Miles and I had a great relationship, and we still do. I have a tremendous amount of respect for him as a coach and as a man.”

Sources told ESPN.com that Miles made a last-ditch effort to get Chavis to stay. But by that time, Chavis’ mind was already made up.

“In the end, you look at it and what’s best for me at this point in time in my career, and it was a no-brainer,” Chavis said. “It was disappointing that we didn’t win a national championship. I certainly felt like we could have. We were close and had some of the better defenses I’ve ever been around even though we had some great ones at Tennessee.

“That’s the thing I’ll miss most, the relationship you had with those kids. I enjoyed that and enjoyed my six years there. What made it even harder was that in my whole career I’d never left a job where the sitting head coach was coming back. But in this case, it was time to move on.”

The timing couldn’t have been any better for Sumlin, who was looking for somebody to transform a defense that had been trampled the last two seasons. The Aggies posted back-to-back finishes outside the top 100 in total defense, placing them at the bottom of the SEC both years. Even more telling, in 16 SEC games over that time, the Aggies allowed more than 30 points 11 times.

“You still have to play good defense if you’re going to win a championship,” Sumlin said. “There’s two parts of that. It’s scheme and coaching, but it’s also talent. There have been some pretty good defensive coaches in this league that don’t have jobs anymore over the last five years. I mean, let’s be honest. The game’s changing, and playing good defense is tough.”

That’s where Chavis comes in. His defenses have finished in the top three in the SEC in total defense 14 of his 20 seasons in the SEC. Of course, what really sold Sumlin was that his high-flying offenses were stopped in their tracks against Chavis’ defenses each of the last three seasons. The Aggies failed to score more than 19 points in any of those three contests.

“I sit in the meetings now and just need to know what he calls it, what the name of it is, because I’ve watched it over and over and over again,” joked Sumlin.

Worth watching will be how quickly Chavis transitions to coaching a program that runs an up-tempo offense. LSU and Tennessee both ran traditional pro-style offenses. For most defensive coordinators who’ve made a similar move, the biggest adjustment is the style of practice and making sure they’re still able to do the things in practice that will allow them to be physical on defense.

It was one of the first conversations Sumlin and Chavis had when discussing the job.

“My standpoint was, ‘Listen, offensively, I’m comfortable. We’re comfortable what we need to do in a practice shell to be successful and do what we have to do to move the ball and score points. I can work around that offensively,’” Sumlin recounted. “But to be flexible, to become a really good defense, what’s that practice look like? We’ve changed the practice plan and adjusted to it.”

Chavis admittedly is old-fashioned, and while he’s well aware that offensive shootouts are what a lot of fans want to see, he said there’s a reason the teams winning national championships are almost always at the top of the defensive statistical categories. Only one of the past 17 national champions has given up more than 22 points per game.

“There’s a lot of teams that can score a bunch of points now, and most teams are running a fast-paced offense, if not all of the time, part of the time,” Chavis said. “You’re even seeing them speed it up at Alabama. That’s just where college football is right now, but you’ve still got to play great defense if you’re going to win a championship.”