In actual play the concept of variance will rear its ugly head and even playing perfect strategy in a positive expectation game (a few video poker variants have this) no human will ever play enough to see those theoretical returns (or losses) except by pure luck. You might also look at some of the 'advantage play' discussions such as Bob Dancer's articles at You can find details on specific game odds on many sites, for example, here's WizardofOdds blackjack calculator: as you can see, with good rules (good luck finding those) and perfect strategy the black jack house edge is considerably less than the 3% you suggest and slots considerably worse, though minimum slot payback is defined by law, in Nevada its 75%.

The publicly held casino groups report as required by law, but I doubt you'll find much detail beyond aggregate statistics unless you have internal accounting access. In Nevada gaming control publishes monthly reports detailing gaming results organized by region, size of casino and game including a breakdown by various slot denominations. You're 'heard' a lot of misleading little factoids.

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