ichthyous - 11:29 pm on Oct 23, 2012 (gmt 0)

This happened to us last year...It was duplicate content (bad coding) and took 3 months to recover. Got hit again this week and the timing could not get worse. Have not lost traffic because of the long tail search but lost rank in the top keywords which we were on the top. It could be over optimized, dup content or anchor text?

This sounds exactly like what's going on with my site. I've never had a penalty of any kind, and my site has ranked well for the terms for years. Never got hit with Panda or Penguin. Whatever algo changes happened around end Sept. or begin Oct. really blitzed my ranking for the most competitive keywords though. I am now middle of third page for terms that I was in top 5 for before, with many many lower PR junky pages ahead of me...makes no sense. The long tail traffic is still there, but the most competitive terms are down 80% or so. My site is showing 750 pages with dupe titles and 950 pages with dupe descriptions now...out of a total of around 7,000 indexed pages, and with 39,000 "not selected" as shown in Index Status...perhaps 1,000 of those are 301-redirected pages...but I don't have anywhere near 39,000 pages on my site altogether. I think this has to do with google finding too many dupe pages and/or too many redirected pages. With so many changes lately how can one know for sure?