FRED:   March 2017
The latest of Google’s confirmed updates, Fred targets websites that violate Google’s webmaster guidelines. The majority of affected sites are blogs with low-quality posts that appear to be created mostly for the purpose of generating ad revenue.

How to adjust: Review Google Search Quality Guidelines and watch out for thin content. If you show ads, make sure the pages they are found on are high-quality and offer relevant, ample information. This is basically it: Don’t try to trick Google into thinking your page is about something when it really is a gateway page full of affiliate links. Most publishers make money off ads, and that’s totally legit as long as you are not cheating.

POSSUM: September  2016
The Possum update ensured that local results vary more depending on the searcher’s location: the closer you are to a business’s address, the more likely you are to see it among local results. Possum also resulted in greater variety among results ranking for very similar queries, like “dentist denver” and “dentist denver co.” Interestingly, Possum also gave a boost to businesses located outside the physical city area.

How to adjust: Expand your keyword list and do location-specific rank tracking. Local businesses now need to be targeting more keywords than they used to, due to the volatility Possum brought into the local SERPs. As you check your rankings, make sure you’re doing this from your target location (or, better yet, a bunch of them). You can do this in Rank Tracker under Preferences > Preferred Search Engines. Click Add Custom next to Google. Next, specify your preferred location — you can make it as specific as a street address.

RANKBRAIN: October 26 2015
RankBrain is part of Google’s Hummingbird algorithm. It is a machine learning system that helps Google understand the meaning behind queries, and serve best-matching search results in response to those queries. Google calls RankBrain the third most important ranking factor. While we don’t know the ins and outs of RankBrain, the general opinion is that it identifies relevance features for web pages ranking for a given query, which are basically query-specific ranking factors.

How to adjust: Optimize content for relevance and comprehensiveness with the help of competitive analysis.