In Jun 2020 the (now sadly deceased) Bill Slawski (thanks again Bill for all your help) wrote a blog on a 2018 patent application r.e. ranking search results based on "information gain" scores.

This Google patent was aimed at addressing the problem "…when a set of documents is identified that share a topic, many of the documents may include similar information." and appears to relate to Google's Helpful Content update of 2022 ("part of abroader effort to ensure people see more original, helpful content written by people, for people, in search results").

See https://www.seolondonsurrey.co.uk/blog/googles-helpful-content-update-information-gain-scores for more information.