It has been said that the hiring of Mike Nolan as Defesnive Coordinator would be for the simple reason that him and Mike McCarthy have a relationship from their tenure in San Francisco. I do believe that relationship will be helpful if they do wind up hiring Nolan (which i hope they do), i do not however think that is the sole reason. Obviously, the 49er's Defense has struggled while Nolan was Head Coach, but if you look deeper you will see, he is a product of the system. For years NFL Franchises have hired Coordinators as Head Coaches in hopes of fixing their respective problems on either side of the ball. What history will show is that this is not an automatic fix:

Marvin Lewis: former defensive Coordinator of one of the best Defenses ever. the Super Bowl winning Baltimore Ravens. Tenure in Cincinatti, yards per game on defense

2004: 19th

2005:28th

2006:30th

2007:27th

2008:12th

not the best Defensive statistics for one of the best Defensive Coordinators ever.

Eric Mangini: a prodigy of Beli-cheat that hepled come up with defenses that led to other teams watch at home, the construction of the Patriots dynasty. yet his defensive statistics in New York were Pedestrian. scoring defense

2007: 19th

2008: 18th

an an average performance. yet still etter than the previous Lewis' record even though more was thought of Lewis.

And the Flip side. Mike Mccarthy was the Offensive Coordinator for the 28th worst offense in the league when the Packers hired him a Head Coach. Now the Packers have one of the more productive Offenses in the League. Scoring Ofense

2007:5th

2008:6th

the List goes on. the one crucial thing to remeber is Head Coaches do not run as many X's and O's as people may think. that is what the Coordinators are paid for. The Coach is in charge of getting his players developed and motivated.