Eric Mangini Hire Not a Home Run for 49ers, but Defense Remains Potent

It's a period of great upheaval in the Bay Area, as the San Francisco 49ers try to shake off a disappointing 2014 season that led to the departure of head coach Jim Harbaugh.

New head coach Jim Tomsula and general manager Trent Baalke have settled on a defensive coordinator, and while the hiring of Eric Mangini may not draw raves, the 49ers have little to fear on that side of the ball in 2015.

ESPN's Adam Schefter broke the news that the 49ers were set to promote Mangini, who spent the last two seasons as the 49ers tight ends coach, to the club's top defensive spot:

Now, making an offensive coach the defensive coordinator may raise an eyebrow or two with some casual fans. It inspired a bit of levity from the San Francisco media:

However, this isn't the Eagles hiring Juan Castillo in 2011. Far from it.

Mangini may have coached on offense the past couple of years, but it's on the defensive side of the ball where Mangini made his bones.

Year(s)	Team	Position
1996	Baltimore Ravens	Offensive Assistant
1997-1999	New York Jets	Defensive Assistant
2000-2004	New England Patriots	DB Coach
2005	New England Patriots	Defensive Coordinator
2006-2008	New York Jets	Head Coach
2009-2010	Cleveland Browns	Head Coach
2013-2014	San Francisco 49ers	TE Coach

It was Mangini's work with Bill Belichick in first New York and then New England that made Mangini the NFL's youngest head coach at the time when the Jets hired him in 2006. It was Mangini's defensive acumen that earned him a second bite at the apple in Cleveland in 2009.

And from a strictly X's-and-O's perspective, it's easy to like this move for the 49ers.

When Tomsula was hired, there were reports that the entire coaching staff was going to be overhauled, and that the 49ers were considering the switch to a 4-3 defensive front.

Granted, the latter could still happen, as Mangini has some experience coaching the scheme from early in his career. However, most of Mangini's defensive career has been spent running a fairly straightforward 3-4 defense.

A defense that in many ways is similar to the scheme the Niners have been using for years.

I get wanting to make the switch. I get wanting to get Chris Borland, Patrick Willis and NaVorro Bowman on the field at the same time without sacrificing snaps for Aldon Smith and Aaron Lynch.

With that said, though, the Niners have been running some permutation of the 3-4 for the better part of the past decade. There have been an awful lot of personnel decisions made with that front in mind.

Whether the growing pains involved with that significant a switch gave Tomsula and the Niners second thoughts or the team is still considering and wants a coach well equipped to bridge the gap, Mangini is a good fit.

Also, while the idea of blowing up the staff may appeal to some (fresh starts and all that), the idea of a first-time head coach having some familiarity with one of his coordinators (who just so happens to have head coaching experience) isn't necessarily a bad one.

Unfortunately, that's also where this whole thing just might go awry.

Over the years, Mangini has developed a reputation for rubbing people the wrong way, from his colleagues to his players. Former player Nate Jackson ripped Mangini in his memoir (via Cleveland Scene), stating that the climate he created as head coach in Cleveland was completely insufferable:

"

Meanwhile, I'm catching some weird vibes around the building. Things feel off. I'm focused on learning the system as fast as I can, so I don't have a lot of time for psychoanalysis, but it's hard to miss. To a man, the entire Browns team seems to be deep in despair. There is a natural sluggishness that occurs during training camp, but this is something different. The men seem positively broken. They have no fight left in them. The locker room is quiet, so quiet. In Denver, even in the midst of training camp, the locker room was lively and social. Cleveland is a mausoleum.

"

Okay then.

Mangini also didn't do his career any favors when he blew the whistle on his former boss. Remember, it was Mangini who brought about Spygate, a decision he told ESPN's NFL Live (via Michael David Smith of Pro Football Talk) in 2012 he regrets:

"

If there is a decision I could take back it’s easily that decision. Never in a million years would I have wanted it to go this way. It’s disappointing whenever it comes up. It’s regret, it’s disappointment, it’s all of those things. Because I know what it took to win those Super Bowls and I have so much respect for the people that were involved there. I’m disappointed that this is what it’s translated into.

"

Well, Mangini's getting another chance in San Francisco now, and he told Matt Maiocco of CSN Bay Area he feels spending a couple years away from defense will serve him well:

"I like the idea of working on offense. I did that my first two years in the league, and I think that'll make me a lot better overall coach because it gives you a totally different perspective."

With luck, that won't be the only perspective Mangini has gained throughout his coaching journey. Even though he's only 44, if this stint goes badly for Mangini, his odds of his ever climbing back into the big chair aren't especially good.

In that respect, though, Mangini lucked out. He gets a defense loaded with veteran talent. From Willis to Bowman to safety Antoine Bethea, the 49ers are a defense filled with pros' pros.

Well, and Aldon Smith.

Mangini's best odds at success in the Bay Area may not even lie in what he does but what he doesn't do.

Don't let ego in the way. Don't alienate the players. Essentially, don't fix what wasn't broken to begin with.

Do that (or don't, as the case may be), and Mangini and the San Francisco defense will be just fine.

Gary Davenport is an NFL Analyst at Bleacher Report and a member of the Fantasy Sports Writers Association and the Pro Football Writers of America. You can follow Gary on Twitter @IDPManor.