It was late Friday afternoon when all webmasters were about to leave for the weekend after a tedious week of understanding Google’s Hummingbird. But, Google had some other plans. Google turned up with the Google Penguin 2.1 update.

Penguin is also known as spam-filtering algorithm and had its first update released in its second generation. The new release affected around ~1% of the web search queries.

The earlier Penguin update was known as Penguin 2.0. It was released on May 22 and it had affected ~2.3% percent of web queries. At the launch, Matt Cutts had explained that it was not a data refresh but an algorithm update.

“It’s a brand new generation of algorithms,” Cutts said in May. “The previous iteration of Penguin would essentially only look at the home page of a site. The newer generation of Penguin goes much deeper and has a real big impact in certain small areas.”

Matt Cutts in his blog has mentioned, that the new penguin 2.1 update will affect to those websites which are not using genuine content and are stuffing the keywords inappropriately in the content. He also mentioned that the effect will also be seen on the websites that use unusual linking patterns.