We have rolled out a change in response to our new default SERP fetching depth of 2 pages. The first 2 pages in SERP collection is our new standard depth.

This means that if your sites are not ranking in the first 2 pages, the denominator for the average ranking in those cases will be 21. This is done in order to prevent overly optimistic average ranking values for keywords that do not rank. If we did not include those non-ranking keywords in the average, it would create the false impression that your overall average ranking was higher than it actually is.

We will be sending out an email announcing these changes, as well as a blog post. Please contact support or your account manager with any questions.