And that's what your search impressions and rankings can look like when you get hit by Google's Product Review Update. That's the Site 1 Case Study.
The image shows the first full week after the Update and the full week prior. The solid lines are April 8-14th and the dotted lines are April 1-7th. You can see that it wasn't a sudden drop on Day 1 of the Update, but it was gradual and is flattening out. Let's see if this is the lowest it'll drop or if the 2nd week of the Update will bring it down some more.
The funny thing is that the majority of the positions didn't drop all that much. My Position 1-2s dropped to 6-12. The 6-12s went to 15-25. The 15-25s went to 30-50+. I didn't see any keywords that dropped completely out of the SERPs. So even though the rankings for individual keywords didn't drop that large, it was enough to lose a lot of clicks and traffic. Position matters.
In other news...Ezoic Site Speed Solution: Leap is out there now. Check your Home Dashboard if you're with Ezoic already. I haven't had time to play with it much, but I do like that they'll show me the tech (themes, plugins) that's not optimized for speed.
There appear to still be a few bugs. Ezoic says there're plugins affecting my site, but they don't exist on my site. I requested a rescan of the site, but not sure it actually performed a scan, because their optimization suggestions didn't change. But I do like that they offer Alternatives for various plugins and themes that they suggest need improvement.
I can see they're trying to make it as user-friendly as possible. Worthwhile to check out.