Google also had a "Cores That Don't Count" paper on so-called "mercurial cores" https://news.ycombinator.com/item?id=27378624 https://news.ycombinator.com/item?

Google also had a "Cores That Don't Count" paper on so-called "mercurial cores" https://news.ycombinator.com/item?id=27378624 https://news.ycombinator.com/item?id=27378624 as well as a presentation https://www.youtube.com/watch?v=QMF3rqhjYuM https://www.youtube.com/watch?v=QMF3rqhjYuM