Sudden fall in Index Status correlates with fall in rankings

[rag_gupta]

I've two sites. The first one had been stable for 10 months. It's a govt job site. But suddenly one day( in Feb/2014) the traffic fell by 90%. At the same time I observe it's Index Status graph tumble down.

Here is the graph [docs.google.com].

Similar story with my another site which was new but went ok for 5-6 months.

I've never worked to build even single back link or even optimize the site.

Here are the GA stats for the first site.:
Bounce Rate: 50%
Pages/session: 2.87
Avg Session Duration: 3:46



So Google Index falling in the GWT should be proportional to fall in rankings.

I can guess that Google index falling could be due to duplicate content, thin content etc. But it took so many months to realize it!

Another theory I've is that it is the Google's Panda( now built-in ) which has drowned my sites.

[aristotle]

So Google Index falling in the GWT should be proportional to fall in rankings.

Do you mean that both must have the same underlying cause?

I can guess that Google index falling could be due to duplicate content, thin content etc. But it took so many months to realize it!

Do a lot of the pages have thin content and/or similar content?

[rag_gupta]

Aristotle! While one site is about jobs the another is about admission courses. I've not created any thin content though but tags may create it.

I can think only of Panda to devalue the sites, there no other reason I can think of. They both have hardly any backlinks.

I've designed sites to help the visitors without thinking of Google.

[not2easy]

Maybe I am confused, but I thought Google Index charts in GWT shows the number of pages on the site that Google has indexed. So a fall in that Index shows that fewer pages are being indexed.

That is not always a bad thing. If you had noticed any problems of Google indexing search results pages or directories that you did not want to have indexed and took action to prevent indexing (like meta tags for noindex or Disallow in robots.txt or via URL parameters) then a falling index shows you some success. That depends on whether all your pages were indexed and you had hoped they would remain indexed and no pages were indexed that should not be.

When you say "I've not created any thin content though but tags may create it." are you referring to WordPress Tags? Those are usually best noindexed or Disallowed in robots.txt because they can serve duplicate and sometimes loosely related content. Great for humans using Search on your site, but not usually great pages to index.

[rag_gupta]

not2easy but can content created by those tags attract sitewide penalty?

Secondly is it possible to know which URL's(from the sitemap) were disregarded and discarded by Google. That could tell me sudden fall in the index.