Comment by westcort

I created a Google custom search engine for the text of about 40,000 out-of-copyright books: https://www.locserendipity.com/Google.html and noticed that exact text matches don’t always show up. A RegEx search of the same repository yields many more matches for specific phrases than the Google custom search does. About a year and a half ago, the quality of results went down a lot. I agree something has changed for the worse.