“John Mueller said that yes, Google does document all of the modifications it makes however he included that it is hard, even for internal Google functions, to use that to figure out why a modification took place to a particular URL. We do track the modifications we make and we attempt to figure out what all is altering over time. Because these things are authorized at some point and released at some point and when you look at a specific URL and you see modifications there, it is really difficult often to track back, even on our side, which of the modifications had an impact here and what triggered this distinction in rankings.