777, I think I misunderstood your post. To be more clear, the main difference between video poker and other slot machines is the legal requirement in Nevada, Louisiana, and some other jurisdictions requires that the cards to be dealt randomly so that every unseen card has the same probability of appearing at any time. This makes it possible to accurately calculate a game's "payback" (Expected Return or ER) and to develop a strategy that an average player can follow to achieve very close to that calculated ER. Many other calculations are possible. For more information, please visit my website at
www.optimumplay.com.
Some video poker games, found mainly in Las Vegas outlying "locals" casinos, offer over 100% ER. There are online forums that list surveys of good games. Player's club points, comps, free play and other promotions add to that, often making sub-100% games such as the original Jacks or Better (a 99.6% game) attractive. As an overall generality, video poker is almost always better payback than reel slots in the same casino, which is why many casinos offer higher point multipliers on reel slots than on video poker.
Video poker is unique as the only casino game where it is possible for the average player to have an advantage on every play.
Such calculations are not possible on other slot machines because it's perfectly legal for each symbol to have a different probability, and there is no requirement for the casino to reveal those probabilities. Therefore, it is impossible to know a game's payback unless you are on very good terms with the slot director. It's even common for two apparently identical machines to have different payback.