Last month in June 2015, the Google team has again announced that they are planning some remodifications on the Penguin algorithm so it runs on a permanent basis. Which is good i guess since they have assured the upcoming changes won’t be any manual actions to change the ranking pattern, on the contrary the data will be continuously refreshed all the time. Though it doesn't imply a website owner can just sit and relax to reap the fruits as there may individual websites still be affected with massive ranking losses all of a sudden. So SEO experts will have to work consistently towards keeping their backlink profile ever clean and legit in the eyes of Google. Otherwise all the backllinks will be futile, if they appear to be inactive or inaccurate. Not to mention about the content quality...it is still the number one weapon to rank up well.