Ratings here at BeerAdvocate can be a bit daunting. The following will help explain the basics used for both Beers and Places. BeerAdvocate Overall Score (BOS) The BOS is a proprietary weighted point (not percentile) system that represents the final overall score for a beer or place. Its purpose is to help make some sense out of the rAvg (1-5 based review average) and provide consumers with a quick reference when comparing one beer or place to another. BOS Range 95-100 = world-class 90-94 = outstanding 85-89 = very good 80-84 = good 70-79 = okay 60-69 = poor < 60 = awfulNotes: A beer or place must have 10 or more reviews in order to receive a BOS. Individual member reviews are not given a BOS. WR (weighted rank) A Bayesian estimate that pulls data from millions of user reviews and normalizes scores based on the number of reviews for each beer or place. The WR represents the beer or place's score against all others. WR is used to help generate the BOS. What's the "BROS" score? From 1996 to 2000 the only ratings and reviews on the site were from BeerAdvocate founders and brothers Jason & Todd Alström. It's a nod to those early days and provides some comparison to the BOS. User Ratings (Beers) Check out: How to Review a Beer. User Ratings (Places) Similar to beer ratings, we break places down to 5 ratable attributes. atmosphere (vibe) = 10% quality = 30% service = 25% selection = 25% food = 10% If a place doesn't offer food, or the rater doesn't include a food rating, the 10% is spread across the other attributes. rAvg (review average) The numerical review average, based on the sum of all user ratings divided by the number of reviews. It's range is 1-5 with a two decimal range for accuracy. pDev (percent deviation) Is the percentage of deviation within the ratings. In non-geek terms, it represents a kind of "average deviation from the mean," and helps to validate the review average. The higher the pDev the more overall deviation from the review average (rAvg), which would be a sign of wider spread within the distribution of ratings, while a lower pDev would indicate more of a consensus within the ratings. rDev (review deviation) The individual reviews current deviation from the review average (rAvg), represented as either a positive or negative percentage. As the rAvg changes, so does the rDev. Quality Assurance No system is perfect, however, we take several steps to ensure that our rating standards are fair and as high as we can currently make them. A Beer or Place must have 10 or more ratings before being assigned a BOS. Weighted ranks help curb abuse and reinforce the validity of the average by using the power of numbers (ratings). As of December 16, 2014, we use an outlier detector that prompts users to provide a written review (text) if they rate a beer or place extraordinarily high or low when compared to the average. Ratings that are bogus or attempt to undermine our system are deleted upon being reported or found. We take this very seriously, and often times the user account will be warned or banned. IP addresses may be cross-referenced to identify multiple accounts too. Retired beers are no longer considered when calculating site-wide averages. Neither advertisers, sponsorships, or industry relationships influence ratings/scores given by @BeerAdvocate and its founders, @Jason and @Todd. You don't have to believe us, but it's been a fact since 1996. We're also constantly reviewing our standards and will make adjustments when needed. Cheers!