I experienced a recent near-site-wide drop in all rankings. The keywords in Google now show up in the depths (around ~500-600 for many) but return the incorrect page. For example:
keyword "best red widget" was ranking #1 for "www.website.com/best-red-widget"
Now keyword "best red widget" ranks #550 for "www.website.com/sony-red-widget"
The "best-red-widget" page is nowhere to be found in the top 1000. Completely gone, as though it has been filtered.
In another case, this is happening similarly, but while the wrong page is ranking in the depths, the real and targeted page is still in the serps, but low.
Another keyword sits around #40 but for the completely wrong page. Several other vaguely-related pages sit also in the SERPs, around ~200. The intended page is nowhere to be found in the SERPs.
This isn't the case with EVERY page on the site, but with the vast majority of them. Some pages dropped in rank severely but still display the proper page in the SERPs. Others that weren't ranking well (~80 or so) didn't budge.
Of interest, searching for my brand (brand is domain name) brings up my Facebook page #3, but the actual domain is page 9 and ranking for a subpage and not the main page. The main root domain isn't even in the top 1000. I don't exactly know if this was the case before the drop because I wasn't paying attention. Google searching the full site with TLD gives me my site at #1.
Considering all of the above, I believe I have triggered some kind of automatic filter/penalty.
I've experienced this several times before on different sites, almost always coming out of it, but I have no idea exactly how. Sometimes I just did nothing, and other times I went to extremes and completely changed the theme/layout of the website, but I don't know if that had anything to do with it.
General Timeline:
December 1st: Drop for some targeted pages. From 1st page to about 50th page, now displaying the completely wrong page.
Jan 2: Noticed that many of my pages somehow lost their correct H1, title and meta tags. Fixed this.
Jan 12th: Complete recovery; many pages now on 1st page again. Not sure if it was related to the fix on Jan 2, but it's the only significant thing I had logged in that time. Hesitant to attribute it solely to this.
This happened for some of my site around December 1st, and it seemed to recover again around Jan 12th. The one thing I noted in my log is that around Jan 2, I noticed that many of my site's pages had somehow messed up and were not displaying a proper title/H1 tag, which I fixed.
Then, around Jan 24th it happened site-wide. It has yet to recover or show any sign of improvement.
Does anyone have any suggestions or comments? I'm considering moving the entire site to a new domain, because this is really bothering me.