A week ago we wrote about Google’s Mysterious Position Six Penalty. The phenomenon described has now been confirmed by Google’s Matt Cutts in one of our Sphinn threads on the topic. It appears from Matt’s comments that the drop for pages impacted was an “unintended consequence,” as Glengara puts it in a WebmasterWorld thread, to the December 2007 Google update.
Matt confirmed the behavior and said Google has already begun reversing it. If you are stuck in the position six penalty, you will most likely see it reverse itself within the next few days.
When Barry asked me about “position 6″ in late December, I said that I didn’t know of anything that would cause that. But about a week or so after that, my attention was brought to something that could exhibit that behavior. We’re in the process of changing the behavior; I think the change is live at some datacenters already and will be live at most data centers in the next few weeks.
In general if you think a site might have a penalty (perhaps from past behavior) and you think the site is clean presently, you can do a reconsideration request in our webmaster console to ask Google to take another look at the site.
This is one of the many reasons why so many SEOs recommend that you hold back on making drastic changes to your pages if you see a drop in rankings. Sometimes it is an issue on Google’s side, and they make a change that you simply cannot control. In this case, those that sat back for a couple months will see things return to normal within days.
I have some more history on the effect at the Search Engine Roundtable.