## Slots and Keno

In playing Keno, at specified times 20 winning numbers are selected by means of table tennis balls drawn from a cage and the numbers are lit up on the scoreboard.

Between times a player can back numbers of his choice. There are various combinations possible; he can back one number, two numbers or groups of numbers up to 15. By far the most popular bet, which accounts for 80 percent of the business, is a group of ten numbers, known as the 20-spot ticket.

If all ten of the player's numbers appear in the winning 20, he will be paid out the apparently splendid odds of 25,000 for 1. Nor does it end there--- if he has nine numbers right he will get 2,800 for 1; eight numbers right pays 1,400; seven numbers 180; six numbers 18 and and five numbers 2.

If four or fewer numbers are correct, the ticket is a loser. To put these odds into perspective, it can be calculated that the chance of all ten of a player's numbers appearing in the 20 chosen out of 80 is one in about 9,000,000.

The player on the 20-spot ticket will collect about once in 15 times, and over 80 percent of these wins will be of one unit only. A player betting on just one number will be paid $3.20 for a $1 ticket if that number is among the 20--- odds of 2-2-1.

The correct odds are 3-1, and the bank's advantage is 20 percent. The bank's advantage on all the Keno bets varies little from 20 percent, so it is an unattractive game from the punter's point of view.

Also, slot machines can be likened to lotteries. The player puts a coin into a slot and pulls a handle which spins three wheels, each containing 20 symbols (not all different--- some symbols appear a few times on each wheel and there may only be six different symbols in all).

When the wheels stop, three symbols, one on each wheel, are showing, and the machine is made so that certain combinations, usually about ten, will pay off a certain number of coins.

The symbols used are usually fruit--- cherries, plums, oranges, etc. If there were only one cherry on each wheel, the chance of getting the three cherries in the line showing would one in 20x20x20, or one in 8,000.

This might be the jackpot line, paying, say, 200 coins. It might be that another winning line is three oranges. The winning lines are decided arbitrarily. So are the payoffs, and they may bear no relation to the probability of the lines.

Unless one knows how many of each symbol are on each wheel, it is impossible to calculate the percentage profit the slot machine will make--- obviously machines can be manufactured to make the percentage profit required.