Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
In looking through this book, I see what is covered is the best of each state. I live in Washington state so I am familiar with many of the recommendation which are spot on. Oregon is where I prefer to fish and some of the places to be where I like to fish. I look forward to fishing the others.