The traditional game of keno came out of a China’s gambling city of Macau in the mid-19th century. The city was ruled by Portugal at the time, so it appears the lottery game was transplanted to China in 1847 or a few years earlier. 1847 is when the first mention of lotto games in China entered the written record, though gambling legends suggest the game came much earlier (even funding the Great Wall of China).
The earliest sheets used the first 80 characters in a famous Chinese poem known as the Thousand Character Classic. “Characters” are the Chinese equivalent to letters of the alphabet, though their language uses symbols to convey a meaning, not build words. When the game was transplanted to the United States, draws for keno used lottery or bingo style balls painted with these (or other) characters, which were drawn out of a hopper or other randomizing container: either rabbit ear blower, an automated blower called an “AKV”, or a spinning metal ball cage called a hand cage.
In time, the numbers 1 through 80 became standard in Western casinos.
The game uses a pay schedule much like you would see on poker machines or video poker games. Each number of catches comes with a different size payout. This payout number is multiplied by the amount of money you wagered. If you bet $2 and the payout says 10, you win $20.
These pay schedules go up to the maximum number of catches, though players can’t expect to win beyond a 15-ball catch. Gamblers need to know you never win back your stake, even if you win.
RNG Design and Keno
Most lottery games in the West use somewhere between 38 and 55 number possibilities, with 6 numbers drawn. Increasing the number options to 80 and having 20 balls increases the possible combinations to astronomical proportions. The odds of hitting all 20 spots is 1 in 3.5 quintillion, a number so far removed from our common everyday experience that it’s impossible to imagine.
With such a high number of possible outcomes, the keno RNG needs to be able to calculate and spit out numbers at a lightning fast rate. Remember back to discussion to the reel positions of pokies and all the possible symbol combinations. Now think of all the possible combinations which have to be counted up in this game and you’ll see why the keno random number generator has to handle a much larger number of calculations. Quintillions of options must be randomized.
Thousands of results are produced every second. When the keno draw occurs, the RNG chooses the number current for that split-second and matches it against the 20 spots chosen for the corresponding number in the sequence. That’s how a keno result is reached with an RNG.