The slot patterns aren't random -- you can predict at least the left slot 100% of the time. The starting slot may be different, but it's the same loop.

I've recorded some of them here -- feel free to add to this sheet: https://docs.google.com/spreadsheets/d/1q9au0iOL_U2sg35RLlPd8W674FPn7_zLbjCr5lGMMsE/edit?usp=sharing