User blog comment:Brandon Rhea/How we're testing the fandom.com domain migration/@comment-31955138-20180927230603/@comment-20644-20180928155645

We'll be comparing them to other communities with the HTTPS changes, but that's not the main point of comparison. The emphasis is on studying the keywords that we're tracking and seeing how those communities continue to rank amongst other websites.

How those communities compare to one another isn't as critical as how they compare to other websites that also have the same keywords.