I read this in the wash posts' "DC Sports Bog" after the Detroit game. It's a very revealing read for those like me that have only watched Shanahan's career from afar until recently. Take a look, Shanahan has made pretty brash qb decisions over the years:
D.C. Sports Bog - A short history of Mike Shanahan benching his quarterback
On a side note, this blog is becoming more newsworthy than Skins Insider. Steinberg's intent is humor, but in poking fun at things he actually does some research that brings things to light like this.