Playing middle linebacker in the NFL means you are the quarterback of the defense. One must be cerebral enough to make the play calls and defensive audibles, have the toughness to lay a bone-crushing hit, and have the ability to be a leader.
Guys like Dick Butkus, Jack Lambert, Mike Singeltary, and Ray Lewis all had legendary Hall of Fame careers making plays from the middle of the field. One key characteristic that every good defense has is that they have a stud middle linebacker routinely making plays.
Anyone who watched a Washington Redskins game from 2007 to 2013 would have noticed a middle linebacker roaming around making what seemed to be every play.