It’s a book about the evolution of football: Amazon.com: The Blind Side: Evolution of a Game: Books: Michael Lewis.
For those of you who haven’t read Michael Lewis’s books, they are amazing. I first found Lewis through his book Liar’s Poker, about Wall Street. But after also reading The New New Thing (about Silicon Valley and Jim Clark) and Moneyball (about Billy Beane and quantitative approaches to baseball), he’s become one of my favorite authors.