To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
Rating is for format not book itself. Don't bother with this newer trade paperback format. It's the same size book printed in a larger book format. Hard to read, blurry type. Just grab a used original paperback because this isn't worth the price even if it's New.