The last update to Google’s Penguin update was Version 3.0, which landed back in 2014. Last time Google said penguin would affect less than 1% of US/UK searches. With that being the case, then Penguin has definitely grown up in 4.0. Google announced the new version on September 23rd, 2016, stating that Penguin is now part of their core algorithm.
For the uninitiated, Penguin was first launched by Google in April of 2012 to catch sites spamming the search results. Specifically the ones who used link schemes to manipulate search rankings. Before Penguin, bad links were devalued and needed to be replaced in order to recover search rankings. Penguin made bad links a more widespread problem, requiring a detailed link audit and removal or disavow of those bad links. Afterward, a penguin refresh was needed, which could take a while. Thankfully that is something that has been addressed.
Perhaps the most important part of this Penguin update, is that Penguin is now real-time. In the past, if your site was affected by Penguin, a simple recrawl of your site after you fixed the issues would not fix your standing with Google. That Penguin specific refresh could take months. Now, Penguin data is refreshed in real time. This means any changes to your standing will take effect as soon as the page has been recrawled and reindexed.
The other significant update states that Penguin now devalues spam by adjusting ranking based on spam signals, rather than affecting the ranking of the whole site. This means any penalties are delivered to a specific page, rather than your entire domain.
While this is an important update to Penguin, it is important to remember that Penguin is just one of more than 200 signals Google uses to determine rank. This makes it easier for us to address a site or page that has been affected by Penguin, but if you are focusing on creating amazing websites without spam, you shouldn’t be hit by it in the first place. You can read more at Googles announcement post here.