Joyner aspires to be the Bill James of football. Though Blindsided is an interesting book for the average fan who wants to read opinions about the game, I don't think Joyner is anywhere near James as a statistical analyst.
Of course, football is very different from baseball. It isn't difficult to isolate and analyze pitching and hitting while controlling for a small number of variables, but it is nearly impossible to statistically compare individual performances in a sport as team-oriented as football. The stats of a running back depend on his blockers and the offensive philosophy. The stats of a linebacker depend on the scheme implemented by the defensive coordinator. And as the titular chapter shows, the stats of a lineman depend on the abilities of his fellow linemen.
In most chapters Joyner starts off with some statistical analysis and then gives his opinions. One can't help but wonder whether the stats are selected or massaged to match the outcomes he wants, a cynicism bred by too much statistic abuse. Plus a lot of the statistical analysis is pretty basic; it seems to get weaker as the book progresses. To determine who should be in the Hall of Fame as well as to resolve other disputes, he merely counts the number of times a player was named All-Pro. That's the kind of analysis I did collecting football cards as a fifth-grader. It's been many years (decades) since I read The Bill James Baseball Abstract, but I seem to remember that book having a lot more math, as one would expect in statistical analysis.
Blindsided is decent for what it is, but I'm disappointed because of what I expected and what it could have been. Instead of really pushing the statistical envelope, Joyner comes across as just another sports fan with strong opinions. Still, he offers some alternate ways of considering questions and makes some good points. Most football fans will learn something worthwhile, but the statistically obsessed probably will be disappointed.