The Fairplay Campaign have recently done a lot of research recently into fruit machines, using emulators for various machines (which you can dowload from the site and try for yourself). Their conclusion will probably come as no surprise to anyone, (particularly anyone who spends time around Daz). It seems there really is no such thing as random chance with the fruit machine – the same sequences of symbols / numbers keep coming up again and again. If you gamble high, it will come in low (or vice versa), unless it has decided that you are going to win beforehand.
The Campaign feel (somewhat justifiably) that this is fraudulent – if the die is showing a 10 (out of a possible 12), the odds of winning a Hi/Lo gamble should be significantly better than they usually appear to actually be (absolute zero).
Alternatively, if you really want to stay ahead of the game, you could not play the mahcines in the first place.