Casino Business' Goal: Win, But Keep It Fun; Thanks to law of large numbers, even a narrow edge will always pay off.(INDUSTRY SNAPSHOT)(BEHIND THE NUMBERS)

Byline: BRIAN DEAGON

At its core, the casino business is pretty simple, says Robert Hannum, a professor of math and statistics.

It's all about the mathematical law of large numbers. When one side has an edge -- even a narrow one -- it's guaranteed to win in the long run. That's the case for casinos.

"The more someone plays and the more they bet, the proportion of the money they will lose gets closer to the house advantage," said Hannum, director of the data mining program at the University of Denver.

Virtually every game in Las Vegas is stacked against the player. The only exception would be a single-deck game of blackjack -- a hard game to find in Vegas -- where the odds are even. In several other games, such as craps, the house has a half-percent advantage.

So in gambling it's always, "Player beware." With roulette, the house has an edge of 5%. That means for every $100 wagered, the house will end up with a take of $5.

With slot machines, the house has an average edge of 5% to 10%, though some slots will pay back 99%. The game with the worst player odds is keno, where the house has a 27% edge in its favor.