Keno is as easy to learn and play as slots, and in casino gambling, it does not get any easier than that. Before we talk about how to play keno, let’s talk about its history a little. Begun in China in the 19th century, Keno reached America in the mid-1800s. Today, the game of keno is so big across the country, attracting all ages because of its promise of a huge payout, millions, won on relatively small wagers made.

How To Play Keno – Some Keno Betting Tips

From The Wizard of Odds, here are a few points to ponder in terms of computing probabilities in a game of keno. You can use Excel and the like.

The probability of matching x numbers, given that y were chosen, is the number of ways to select x out of y, multiplied by the number of ways to select 20-x out of 80-y, divided by the number of ways to select 20 out of 80.

The number of ways to select x out of y refers to the number of ways, without regard to order, you can select x items out of y to choose from. This function may be represented as combin(y,x).

Generally stated, combin(y,x) is y!/(x!*(y-x)!). For those of you who are unfamiliar with the factorial function: n! is defined as 1*2*3*…*n. For example: 5!=120. Thus, the number of possible five card poker hands would be combin(52,5) = 52!/(47!*5!) = 2,598,960.

Ergo, the overall general formula for the probability of x matches and y marks is: combin(y,x)*combin(80-y,20-x)/combin(80,20).

To test this formula, let us try to find the probability of getting 4 matches given that 7 were chosen.

This would be the combin(7,4) multiplied by combin(73,16) divided by combin(80,20). combin(7,4) = 7!/(4!*3!) = 35. combin(73,16) = 73!/(16!*57!)=5271759063474610. combin(80,20) = 3535316142212170000. Thus, the probability is: (35*5271759063474610)/3535316142212170000 =~ 0.052190967.

To determine the expected return of an overall number of picks: take the dot product of the return and the probability for each number of winning catches. For example: the pick 5 at the Atlantic City Tropicana pays 1 for 3 catches, 10 for 4, and 800 for 5. Thus, the return is: 1*combin(5,3)*combin(75,17)/combin(80,20) + 10*combin(5,4)*combin(75,16)/combin(80,20) + 800*combin(5,5)*combin(75,15)/combin(80,20) = 0.72079818915262.