It appears that Google may have made some sort of update to their algorithm for search rankings on November 14th, 15th.  Many people are speculating as to the impact of this update and if it was related to the Google Hummingbird.  Moz.com reported on various research findings and possible theories being Google DNS issues substantiated by Webmaster Tools errors on November 14th for multiple users.  More likely theories pertaining to smaller sites receiving penalties boosting ranking of bigger sites and even a better concept of mobile traffic search results having a bigger impact.  Read more about the Nov. 14th Google update >