Keno has the highest house edge — and therefore the worst odds for the gambler — of virtually any game at the casino. At a minimum, the house will keep 22 percent of every keno dollar wagered. Sometimes the house edge is as much as 50 percent, making it a very poor wager for the player.

Various mathematicians have calculated the odds of matching the numbers you play against the numbers drawn in a given keno race, and the odds grow exponentially with the amount of numbers you select. For example, if you play one number, the odds of that number being among the twenty drawn are about 3 to 1. If you play two numbers, the odds of matching one number are a little more than 1.5 to 1, but the odds of matching both numbers are nearly 16 to 1. Play five numbers, and the odds of matching all five leap to 1,550 to 1; play ten numbers, and the odds of matching all ten explode to 8.9 million to 1. Your odds of matching 15 numbers — the amount required at most casinos to win really big money — are less than 400 million to 1.

These almost insurmountable odds are why experts advise keno players to look on the game as nothing more than amusement, a low-cost way to see some action or a restful break from the blackjack, craps, or poker tables. That way, if you aren't lucky enough to hit it big, at least you have enjoyed yourself.