He did a great job as an analyst explaining many of the intricacies of the game and various plays. However due to time limitations of a broadcast he wasn't able to go into detail as to how the players had to do many little things to achieve the results they did. For instance much of offensive and defensive line play is dependent upon hand placement. Which ever one gets it right usually wins that particular play, but even if one player wins his battle it may be irrelevant because a teammate got it wrong.
This has lead to many keyboard experts that love to expound about their great knowledge of the game when they only have a superficial understanding of it. To further exacerbate things he lent his name to a video game that allows all sorts of impossible moves by players and improbable plays.
John, I know you meant well, but the results leave something to be desired.