Measuring the quality of NFL coaching is difficult. Beyond win-loss record, there are no stats. No wins above replacement or adjusted wins, either -- just wins, losses and the occasional tie.
As such, judging the quality of a coaching staff is largely an exercise in anecdote and inference. It's not hard to infer that Kyle Shanahan is a really good offensive coach -- we have the stats for his offenses, and we sure do have a lot of them. But riddling it out for Nick Caley (first-time coordinator), Mike McDaniel (great only with his starting quarterback) and Kevin O'Connell (unbelievable without his starting quarterback) is a lot trickier.