When people analyze an offensive play-caller in the NFL, they simply look at the overall numbers of the play-caller’s unit and make their judgments based on those alone. If the play-caller’s offense was 30th in scoring, he stinks. If his offense was 5th in scoring, he’s a rockstar.
However, evaluating coaches is a lot more complex than that. There are many factors involved in determining the performance of a unit. It’s never 100% on the coach. He could be let down by poor execution. He could also be made to look better than he actually is thanks to the phenomenal talent on the roster.