Cherries can come up on the left reel 14 percent more frequently than oranges, which in turn come up 3 percent more frequently than plums. In other words, 3 percent more of the random numbers being chosen by the computer chip told the left reel to come up oranges than plums, and 14 percent more of these random numbers told the left reel to come up cherries than oranges. So the computer chip, by taking physical reality out of the game, greatly enhances the variety of games and payouts that can be offered-but it does nothing for the predictability of those outcomes.
One of the major differences between a computerized slot machine and a mechanical one is that, with the mechanical reels, all of the symbols on a reel had an equal probability of coming up. After 1,000 spins, each of the symbols on each reel should have come up about the same number of times. If a slot builder wanted one symbol to come up more often than others, it was simply put on the reel twice.
But this was clumsy. The builder could only make the symbol come up twice as often. The new computerized machines can be programmed so that one symbol comes up more frequently than another, and at any percentage of difference.