My expert <G> says 9/6 = 96% and 8/5 = 93%, saying that this data is not published but calculated, and that "perfect play" will give you about 1% advantage, while anyone with a little knowledge, not playing perfect strategy, will lose about 1%.

Jacks or better option takes 20% away from the player. What a deal! Jokers Wild, Deuces Wild run 92-95%.

Source: "Slot Machine Mania" Dwight and Louise Crevelt. And for anyone who cares, this book is a good read. It goes into the machines, the payouts, how things really work, and addresses the many myths about slot machines.

Interesting tid-bit. In 1967, 80% of the casino revenue came from table games. Now 56% or Nevada casino revenue comes from Slot Machines. In Laughlin, 70% of the profit comes from slot machines. This stands out as something the players should stay away from. <G>

When the Milwaukee casino had a limited number (400 if I remember right) of slot machines, it was the most profitable casino in the world, when looking at the money taken in vs the machines in the casino. Who would imagine that?

So with that... I was wrong about the 87% figure, it's somewhere between 93 and 97%, depending on who's telling the tale.