> I assume there are a lot of games being played in Vegas at far from reputable establishments, where the owners of such places would love to kick the odds in their favor.

Or where a dealer would collude with players for the right price.

> the kind of place where your alcohol is mostly water

The less reputable places would typically have a vested interest in decreasing your judgment and inhibitions, not in keeping you clear-headed. Remember that many casinos will reward high-rollers with free drinks, among other perks.