Gunther Cunningham's time with the Chiefs is really divided into two distinct periods. From 1995 to 1998 he was the team's defensive coordinator. During that time, Kansas City had a truly great defense. During Cunningham's three years as defensive coordinator, the Chiefs allowed the lowest number of points in the NFL; led the league twice in scoring defense; and the defense set a team record in 1997 with only 232 points allowed.
Cunningham also had some amazing players on those defenses. Derrick Thomas, Neil Smith, James Hasty, Dale Carter...the defense was the Kansas City Chiefs in the 1990s.
If Cunningham left the Chiefs after that 1998 season, he would be remembered in a much more positive light than he is now. His mediocre two year stint from 1998 to 2000 as the Chiefs head coach was awkward. He went .500 in those two seasons. Cunningham's success as a defensive coordinator didn't translate to being a head coach.
He came back to the Chiefs as the defensive coordinator in 2004 after being on the Titans staff for a few years. To be fair, Cunningham did inherit a terrible defensive team. Not only that, most of the draft picks made in the years before and during his time in KC would turn out to be disastrous. Here's what the team has been dealing with on the defensive side of the ball in the last 7 years.
In the last 7 years, the Chiefs have spent 4 of 7 first round picks on defense, every second round pick on defense, and 5 third rounders on defense.
And the 2008 team ranked 31st in the league in yards allowed by giving up an average of 393 yards a game.
It would be tough for any coach to deal with failure like that on the personnel side. But Gunther wasn't able to do what any coach needs to do: be successful with what you've got. In 2008, he took over coaching the linebackers and it was one of the most frantic, unorganized position groups on the team. Granted, he did deal with a lot of injuries at the position. His biggest knock is the under development of 2005 first round pick LB Derrick Johnson. Linebackers are Cunningham's specialty and DJ has vastly under performed.
With all that said, I do believe that Gunther Cunningham can be successful in Detroit. He is known for a fiery personality that, if given the right audience, can help win football games. He has lots of experience and has been successful in the past. Unfortunately, he grew stale and old in KC. A new set of players and a new look will be of great benefit to him.
It seems like the general consensus is that Cunningham was great at one time but struggled when he didn't have lots of talent to work with. That is obviously worrying to me because the Lions probably have the least talented defense in football. Even so, maybe a change of scenery will work out well for Cunningham, and maybe his fiery personality will work well to motivate defensive players on the Lions.