Bentley built his Markov chain using his Bell labs colleagues Pike & Kernighan's Markov algorithm from The Practice of Programming

http://books.google.co.uk/books?id=to6M9_dbjosC&pg=PA62&...

Pike had used this technique earlier when coding up http://en.wikipedia.org/wiki/Mark_V_Shaney with Bruce Ellis

I'm sure they were not the first