I don't know much about multiple personality disorder, but it probably doesn't help an NFL player's career. And for a guy who suffered from it, Herschel Walker was pretty damn good.
Walker tells the world that he suffers from the disorder in an upcoming book entitled "Breaking Free." None of his former teammates or coaches were aware that he had the problem ... or any problems at all, for that matter.
It does help to explain, however, why the Cowboys traded so much to get him back in 1989. Negotiations must have gone on forever before the Vikings decided that they could give up 5 players and 8 draft picks, but only if they got all 17 Herschel Walkers in return.
Again, I have no idea how this would manifest itself in an NFL running back. I just wonder if there were times when Walker would take a hand-off, slice through the line, lower his shoulder into a defender, and then think, "Wait! I'm a mild-mannered librarian! Why are you trying to tackle me?! You've got the wrong guy! AHHHHHHH! You will not be allowed to check out books here anymore, sir!"
• Herschel Walker reveals multiple personalities / Yahoo! Sports