Since this is a PFF thread, I thought I'd ask - has anyone read the new book about PFF from Matthew Coller (ex-WGR producer) yet? I'm thinking about it since I've always wondered how exactly they attempt to normalize these grades across the many different things they grade and across all the different graders they employ. I know PFF provides apparently useful analytic data to tons of teams; and I don't really have a doubt they have a bunch of talented numbers guys there. The grading system on the other hand seems to produce head scratching results frequently.
Link to book I'm talking about.