Because those are highly connected with dominant intent, I removed queries in the analysis. I hypothesized as Google is tremendously invested in surfacing specific sites for those questions that purpose could mask some of the consequences. Here is the Exact Same analysis just for the questions with enlarged sitelinks (this yielded a smaller group of 5,064 stable URLs):

On Friday, April 5, after many website owners and SEOs reported pages falling from positions, Google affirmed a bug that was causing pages to become deindexed:

Can it be random or systematic?

Is this over, and what is next?

Considering that each the URLs from the group were stable throughout February, we expect 100 percent of them to appear on February 28 (that the chart bears out). The change over time is not striking, but what we see is a steady drop-off of URLs (a natural phenomenon of shifting SERPs over the years ), using a different drop on Friday, April 5th, a restoration, and then a similar drop on Sunday, April 7th.
The impact of this deindexing bug does appear to be measurable, although we can argue about how”big” 4 percent is. For some thing as consequential as websites falling from Google ranks, 4% is quite a little, but the effect for sites should be minimal. For the time being, there is not much we can do to accommodate — Google is telling us that this is a bug and not a deliberate change.

Performing this is hard, and we have access to historical data, after an event has passed, although google tools can help us check if a page is indexed.  Imagine if we could isolate some URLs, however, that we could reasonably expect to be stable with time? Can we use that place to detect abnormal patterns?
The departure from trend on 7th and April 5th is rather simple to view in the version.

Notice that this metric proceeded very little during March’s algorithm flux, such as the March”center” upgrade. It appears to not be influenced much by Google algorithm updates that are typical, although we can not prove that the steady URL drop represents deindexing.

Here’s the data from February 28, 2019. This graph is the percent of this 23,237 secure URLs that appeared at MozCast SERPs:

At the exact same 90 — 100 scale, it is possible to understand that across all stable URLs were not smaller than the impact, but there’s still a set of April 5th and April drops. It does not seem that these mega-sites were resistant.
Since MozCast just tracks page one, I wished to decrease sound from a URL”falling off” from, say, position #9 to #11. Employing these qualifiers, I had been left with a pair of 23,237″stable” URLs. How did those URLs work over time?

As one of my favourite movie quotes states:”There are no happy endings because nothing ends.” For the time being, indexing rates appear to have returned to normal, and I guess that the worst is over, but I can’t forecast the future. If you suspect that your URLs have been deindexed, it is worth manually reindexing in Google Search Console. Note that this is a tedious process, and there are daily limits in place, so concentrate on pages.
MozCast revealed a multi-day growth in temperatures, such as a 105° spike on April 6. While deindexing would obviously cause flux, as pages fell out of positions and then reappeared, SERP-monitoring tools aren’t designed to distinguish the causes of regular.
Other than variants, the blueprint for URLs appears to be somewhat similar to the analysis. It looks like deindexing’s effects has been widespread.

It’s difficult to ascertain if this bug was arbitrary, affecting all websites or was orderly. It is likely that restricting our analysis to”stable” URLs is skewing the results. On the other hand, trying to assess the instability of URLs is a bit nonsensical. I must also note that the MozCast data collection is skewed toward so-called”mind” terms. It doesn’t contain many questions such as questions, in the very-long tail.

What about dominant intent?

Across the month of February, the MozCast 10K daily tracking set had 149,043 exceptional URLs ranking on page . I reduced that to some subset of URLs using the following properties:

  1. They appeared on page one daily in February (28 total occasions )
  2. The query did not possess sitelinks (i.e. no apparent dominant intent)
  3. The URL ranked at position #5 or even better

Having just changed to contacts, I feel your pain. What is that zoomed-in graph:
Think of it you don’t have time to search down but want to read!
Taking a look from April 4th to 5th at the information that is day-over-day, it looks like the losses were distributed across domains. Of domain names that had URLs on April 4th, roughly half saw a lack of URLs that were ranking. The only domain that experienced day-over-day reduction that is 100% were those that had 3-or-fewer secure URLs in our data collection. It does not appear that deindexing targeted specific websites.

Could you zoom for us older folks?

Is if big sites were affected by the bug. This reduced us to 2,454 stable URLs. Unfortunately, the deeper we dive, the smaller the data-set gets: