Google Drops Review Star Threshold to 1 or 2 Reviews AND Stops Using Bayesian Average

Last week we reported the fact that Google had lowered the threshold for showing review stars in the search results from 5 to 3 total reviews. Over the weekend, numerous reports came in from Europe, Australia and the US of the threshold to showing stars having dropped to 2. That appears to be the case world wide. There are also reports of even one review showing the stars on a business listing but it does not yet appear to be the case universally.

Review Averages Change As Well

Equally interesting to me is that Google is now using the arithmetic average that we all learned in grade school and is no longer using the Bayesian average to calculate the review score. A Bayesian average looks at the larger data set for all businesses to calculate the likelihood of the particular average for a given business being lower when they have few reviews.

The upshot of this change is that a business with a perfect 5 on their ratings with 2 to 10 reviews will now get a 5 star rating. Previously if a business had less than 10 reviews and a 5 Star arithmetic average Google would show a 4.8 or 4.9 rating for that business.

Using the Bayesian average may have been a more accurate statistical picture, but users and small business never liked it and complaints come up repeatedly in the forums. Consumers thought that businesses were cooking the books and the businesses thought that someone was messing with them.

Google’s use of a simple average that both consumers and businesses understand is a welcome change.

Share on Facebook10Share on Google+22Share on LinkedIn24Tweet about this on Twitter

About the Author

Mike Blumenthal
With unmatched industry expertise and knowledge, Mike is a co-founder and serves as GetFiveStar’s Chief Review Officer helping our customers get the most of the platform. Mike is widely cited as the foremost Local Search expert in North America and affectionately known among his colleagues as ‘Professor Maps’.

18 thoughts on “Google Drops Review Star Threshold to 1 or 2 Reviews AND Stops Using Bayesian Average

    • Mike Blumenthal - February 6, 2017 at 5:41 pm

      I can’t see that it would affect rank but it will likely impact click throughs by searchers… 2 reviews with a 2.5 rating or a 1.5 rating is unlikely to even get a second glance where as 2 reviews with no associated rating might.

  1. Ryan Scollon - February 6, 2017 at 5:01 pm

    I wonder what Googles thinking was behind lowering the threshold. It’s great that business will now be able to get the review stars shown much quicker as it requires less reviews, but I also wonder if it will make people lazy as they will now only need to get 2 for it to show.

    • Mike Blumenthal - February 6, 2017 at 5:43 pm

      We can only speculate as to Google’s motivations.

      My thought is that Google wanted to make those with fewer reviews more visible to both the searcher and the business owner. I think of it as a call to action… for the consumer to either click on the listing or no and for the business owner to start paying attention to their reputation.

      Why? My speculation is that with the increase display of rich snippets from 3rd party sites over the past 6 months, Google reviews with fewer than 5 stars were losing visibility.

      But who really knows.

  2. Sara Dunn - February 7, 2017 at 11:27 am

    Super interesting. I’m seeing stars displayed consistently down to 2 ratings, but inconsistently for pages with 1 rating. In a chiropractor search I just did, one doc with 1 rating had stars showing, another doc in the same search with 1 rating didn’t have stars showing. Wonder how this is decided…

    • Mike Blumenthal - February 7, 2017 at 11:33 am

      @sara I was asking the same question. Likely either that 1 review stars are either rolling out OR are a test. But there may be some other logic. Feel free to send me your examples with and without to mike at

  3. Greg Beddor - February 8, 2017 at 7:43 pm

    Too easy in my opinion, now a lazy business owner with 1 good review stands out with a 5 star rating just like their hard working competitor that worked their tail off to earn more than 5 reviews.

    • Mike Blumenthal - February 8, 2017 at 8:31 pm

      @greg that’s from the pov of someone how gotten 5 reviews. Not from Google’s pov.

      Over the past 6 months google has elevated minor review sites to the KP and bumped all of the directory sites with reviews in the organic results.

      And gave them review stars even if they had only 1 review.

      One presumes that from Google’s perspective there is a logic to it.

    • Mike Blumenthal - February 9, 2017 at 11:27 am

      Not sure what exactly is happening there… it could be that the index has not caught up with the actual ratings, it could be that the many ratings don’t carry as much weight as the reviews or it could be as you point out bayesian… but it would odd to use bayesian on negatives but not on positives.

      I think, given the amount of flux and the fact that reviews don’t always keep pace with themselves, we need to revisit your listing in a week or so.

  4. Peter - February 20, 2017 at 6:06 pm

    Hi Mike…I’m a very satisfied GetFiveStars subscriber and have seen my Google review numbers grow but when my company is displayed it in the #1 position with images and shows “21 Google Reviews” We do have a 4.5 rating so I wonder why isn’t this being displayed and my mention of google reviews on the in line organic results don’t appear at all

    • Mike Blumenthal - February 22, 2017 at 10:30 am

      Thanks for your comment!

      Perhaps you could help me understand what you mean when you say: I wonder why isn’t this being displayed and my mention of google reviews on the in line organic results don’t appear at all

  5. Keith Hearn - February 22, 2017 at 11:22 pm

    Hi Mike, You are right google won’t show star rating on 1 or 5 reviews. On my local business listing I have 3 reviews but google don’t showing average rating. Do you have any idea how many reviews google consider to showing average rating.

    • Mike Blumenthal - February 23, 2017 at 11:52 am

      My sense is that “ratings only” do not count towards the average

  6. Joy Hawkins - March 2, 2017 at 10:18 am

    It appears there was a bit of a delay updating everyone’s averages when this rolled out. For every example posted here and elsewhere where the average seemed to be wrong, I’m now seeing it correct.

  7. Rob - March 2, 2017 at 2:58 pm


    Sorry if this is covered somewhere, but just wondered what the latest advice is with regard to linking to a google business listing to allow a review to be left on it. Currently there seems no way for a customer to leave a review by just visiting the normal listing url?


Leave a Reply