between what was being reported about Retzlaff's PFF grade and his grades from other metrics (ESPN's QBR and PER). The gap seemed surprisingly big between those metrics (especially QBR and PFF since they both purport to be based on similar evaluations). If you're able to figure anything out from it, I'd love to hear what you find.

Oh, and FYI, many people don't appreciate my asking questions about grades of our players ... appears that it means I hate them personally or I'm dumb or something.