This has already been mentioned in some threads and I imagine one has been started somewhere. When I search for my main phrase, it no longer matters whether I search in the singular or plural, I am getting the results for the plural. Mine is a local wedding thing. When you search for 'locality wedding' you get the same results as 'locality weddings'. However when searching for 'locality reception' I don't get the same results as for 'locality receptions'. Additionally 'wedding' does not yield the same result as 'weddings'. I wonder what is the criteria for this happening and what decides whether they go with the singular results in both cases, or the plural results in both cases.
It can sometimes be very difficult to say acturatly if the plural is the difference. Lately I have noticed that simply doing the same search from the results page will be enough to trigger a different set of results to be displayed. I assume this is due mainly to the search being carried out on a different server or data center.
The now rolling update process means the index is changing all the time. Makes it very dificult to accuratly carry out comparisons.
Another example is New York wine(s), That could be an example that has always been like that though, since I don't follow it much. The one I mentioned in the opening post I do follow and the singular and plural results have never been close. Searching for restaurants in my area also yields the same results regardless of the "s". That sux by the way. Used to be the individual restaurants would show up in the singular, and the directories would show up in the plural. Now it's only the directories.