According to Google, “the Penguin rollout is ongoing, and this is just the effect of that.”
The Penguin 3.0 rollout began on October 17, 2014, which has been going on now for the past six weeks. This seems to be taking longer than usual, making this rollout a bit unusual in this case. A number of sites that reported changes on that Thanksgiving only saw recoveries. This seems as if there was some sort of reversal of the Penguin 3.0 rollout that first began in October. The exact results that happened on Thanksgiving is still unclear.
Here is the list of dates of all Penguin releases:
- Penguin 1.0 on April 24, 2012 (impacting ~3.1% of queries)
- Penguin 1.1 on May 26, 2012 (impacting less than 0.1%)
- Penguin 1.2 on October 5, 2012 (impacting ~0.3% of queries)
- Penguin 2.0 on May 22, 2013 (impacting 2.3% of queries)
- Penguin 2.1 on Oct. 4, 2013 (impacting around 1% of queries)
- Penguin 3.0 on October 17, 2014 (impacting around 1% of queries)