garyr_h - 12:15 am on Dec 27, 2012 (gmt 0)

The site was hit badly three times, from the original Panda and then December 2011, and then in April/May (whenever that Panda update was, I don't feel like looking it up now). Since August, there has been positive gain from Panda for every update as I have been adding a lot more content to pages.

This update completely "slaughtered" the site, as olaj stated. All the positive gains are gone and it's actually doing the worst EVER.

Is the subdomain the only thing changed?

The site does have a subdomain, used by members to submit their own content. Is that the cause? The content is (at least, 99.9999% of it because I delete all unoriginal content when I find it or someone reports it) original. However, it isn't too wordy. Some of the posts are 100 words or less.

If this is the cause, what is the best course of action? Some of the pages get direct traffic from G while others don't. Should I simply robot.txt all the pages except the homepage and category pages (since those are not user generated)?