A couple of days ago it seems my site was hit with some kind of algorithmic penalty that I can't figure out. I try to only do white hat SEO.

Site is a couple years old, very well ranked for hundreds of keywords. Has ranked on page 1 or 2 of Google for my top phrase for at least a year (pointing to home page). There are lots of inside pages that get well-ranked also, for other phrases.

To explain: say the site is about "blue widgets," and the domain is bluewidgetworldDOTcom. Until the problem hit, it was ranked on page 1 or 2 for "blue widgets," and the Google search result pointed to the home page. The site also has a very long tail, with hundreds of key phrases like "blue widget articles," pointing to inside pages. But suddenly, as of a few days ago, the site no longer ranks at all for the term "blue widgets." Yet that is what the site is about. Also, it appears that some of the long tail keywords that pointed to the home page are also gone or greatly lowered. But the home page has not vanished entirely -- just greatly reduced presence.

The weird thing is that The long tail, pointing to inside pages, is still largely intact, driving about 3,000 visitors a day. I can't figure it out.

Only two things I can think of recently may have affected things:

1. Site has about 4,000 dynamic pages, and until about a week ago, all the description tags and keywords tags were duplicates. We changed how the meta tags are pulled from database, to make all description and keywords tags unique. Title tags on these pages were already unique.

2. Site was hacked into about a week or so ago, and some jerk messed with some database functions. Fortunately, they did not screw it up too badly, and we managed to repair and block access.

Any ides for what might be the problem would be appreciated!

Only two things I can think of recently may have affected things:

1. Site has about 4,000 dynamic pages, and until about a week ago, all the description tags and keywords tags were duplicates. We changed how the meta tags are pulled from database, to make all description and keywords tags unique. Title tags on these pages were already unique.

2. Site was hacked into about a week or so ago, and some jerk messed with some database functions. Fortunately, they did not screw it up too badly, and we managed to repair and block access.
Okay, both changes were made and the site was hacked at about the same time. Makes it difficult to say which might have caused the problem, but seat of the pants I'd go with the hacking.

The changes to the descriptions and keywords *should not* have a lasting impact on rankings, though it might take a bit of time for the SEs to digest them. In the long run they should help to disambiguate pages further down your site's hierarchy in case any of those pages are very similar and might get caught up in a dupe content filter. But, just to hedge my bets here, a change is a change and who the heck knows what effects it might have.

As for the hack I guess it depends exactly what was being output when the SEs accessed pages during that period. Were pages accessible? Did the SEs see the content they expected? Did the hack wind up just plain confusing them?

In both cases I think the best bet for right now is to just sit back and monitor the situation. Any effects from the changes and the hack should sort themselves out in due time.

All that said, keep in mind that there has been a lot going on at Google since the first week in June; what *looks like* and algo update might have taken place. This thread (http://forums.searchenginewatch.com/showthread.php?t=22784) touches on it and also references a thread over at WmW. I'd suggest a read through both and see if any of the changes are of the same type exhibited by your site.

Thanks JimBeetle. I read both the threads you referenced (took me a while!) and while I'm still not sure of what happened to my site, I am leaning to it being part of the disaster that seems to have been happening in June for a lot of sites. This is more so since after my initial post here, I observed several of my competitors had gotten slapped down by Google in a similar manner to my site.

So I laid all that stuff out to add to the discussion, and my post (under the name Ortelius) is on the WMW forum (http://www.webmasterworld.com/google/3663984-14-15.htm).

Thanks again for your input -- I'll come back and post if I get a conclusive answer!