One can opt to accept that all standard industry (IGT, etc.) machines
are fully random -- fairly simulating the mechanics of a card deck --
and focus your energies and efforts on honing your play strategies.
Or, one can have doubts about the fairness of the machines you play.
In this latter case the only rational thing to do is to quit and take
up some other pasttime. To have doubts and yet continue to play is an
exercize in irrationality that surely can only lead to an acute case
of schizophrenia :).
- Harry