Hrqls: I'd make a separate achievement for forcing your opponent to pass 40 times a row in Hyper. ;-) And not count Cloning (40 passes in a row in Cloning Backgammon happens far more frequently than in other types).

Which leads to an interesting question. What's the maximum forced passes in a row you can have in Hyper Backgammon? Or in any other variant with a fixed number of stones? (It clear there's no upper limit in Cloning).