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.
Wasn't sure about the sizing as I had bought women's tops from the same brand that were tight for the person I bought them for. I wear a large and this top fitted perfectly. Comfortable and top quality too.