Ah, yes, Markov chains. A long time agoMark V. Shaney https://en.wikipedia.org/wiki/Mark_V._Shaney
was designed by Rob Pike and posted on Usenet.
And Veritasium's video "The Strange Math That Predicts (Almost) Anything" talks in detail about the history of Markov chains: https://youtu.be/KZeIEiBrT_w