# Dictionary Definition

keno n : a game in which numbered balls are drawn
at random and players cover the corresponding numbers on their
cards [syn: lotto,
bingo, beano]

# User Contributed Dictionary

## English

### Etymology

From French quine, with reference to a set of five winning lottery numbers.### Pronunciation

- /ˈkiːnəʊ/

### Noun

- A gambling game, a variety of the game of lotto, played with
balls or knobs, numbered, and cards also numbered.
- 1971: Memories of this night are extremely hazy. All I have, for guide-pegs, is a pocketful of keno cards and cocktail napkins, all covered with scribbled notes. — Hunter S. Thompson, Fear and Loathing in Las Vegas (Harper Perennial 2005, p. 41)

# Extensive Definition

- This article describes the lottery game. For the radio station, see KENO. For the nuclear criticality code, see Keno (computer program).

Keno is a lottery-like or bingo-like gambling game played at modern casinos. A
traditional live casino keno game uses a circular glass enclosure
called a "bubble" containing 80 ping pong-like balls which
determine the balldraw result. Each ball is imprinted with a number
1 through 80. During the balldraw, a blower pushes air into the
bubble and mixes the balls. A "caller" presses a lever opening a
tube, where the balls lift one at a time into a "V" shaped tube
called the "rabbit ears". The caller and a "verifier" record each
of 20 balls drawn, and the computerized keno system calculates all
wagers based on the numbers drawn.

Players wager by marking an "X" over the "spot"
choices on a blank keno ticket form with 80 numbered selection
boxes (1 to 80). After all players successfully place their wagers,
the casino draws 20 balls (numbers) at random. Some casinos
automatically call the balldraw at preset timed intervals
regardless of whether or not players are waiting to place a
wager.

Each casino sets its own series of pay scale
choices called "paytables". The player is paid based on how many
numbers drawn match the numbers selected on the ticket and
according to the paytable selected with regard to the wager
amount.. Players will find a wide variation of keno paytables from
casino to casino and a large deviation in the house edge set for
each of those paytables. Additionally, each casino typically offers
many different paytables and specialty keno bets for customers to
choose from, each with its own unique house edge. No two casinos'
keno paytables are identical. There are several Reno and Las Vegas
casinos offering as many as 20 or 30 different paytables from which
the player can choose.

The house edge ranges from less than 4% to 66%.
The typical house edge for non-slot casino games is between 0% and
5%

## Keno history

Keno originated in ancient China in the Han Dynasty between 205 and 187 B.C. Chinese immigrants brought the game to America in the 19th century.The word "keno" has French or Latin roots (Fr.
quine five winning numbers, L. quini five each), but by all
accounts the game originated in China over 2000 years ago. Legend
has it that the invention of the game saved an ancient city in time
of war, and its widespread popularity helped raise funds to build
the Great Wall. According to one source, results of keno games in
great cities were sent to outlying villages and hamlets by carrier
pigeon. Eventually, Chinese immigrants introduced keno to the West
when they sailed across the Pacific to help build the American
trans-continental railroad in the 19th century.

## Keno odds

Keno payouts are based on how many numbers the player choses and how many numbers are "hit", multiplied by the proportion of the player's original wager to the “base rate” of the paytable. Typically, the more numbers a player chooses and the more numbers hit, the greater the payout, although some paytables pay for hitting a lesser number of spots. For example, it is not uncommon to see casinos paying $500 or even $1,000 for a “catch” of 0 out of 20 on a 20 spot ticket with a $5.00 wager. Payouts vary widely from casino to casino. Most casinos allow paytable wagers of between 1 and 20 numbers, but some limit the choice to only 1 through 10, 12 and 15 numbers, or "spots" as keno aficionados call the numbers selected.The probability of a player hitting all 20
numbers on a 20 spot ticket is approximately 1 in 3.5 quintillion
(1 in 3,535,316,142,212,180,000 to be exact). If every person now
alive played one keno game every single second of their lives,
there would be about one solid 20 jackpot-winning ticket to date.
If all these possible keno tickets were laid end to end, they would
span the Milky Way galaxy -- and only one of them would be a
winner. Even though it is virtually impossible to hit all 20
numbers on a 20 spot ticket, the same player would typically also
get paid for hitting “catches” 0, 1, 2, 3, and 7 through 19 out of
20, often with the 17 through 19 catches paying the same as the
solid 20 hit. Some of the other paying "catches" on a 20 spot
ticket or any other ticket with high "solid catch" odds are in
reality very possible to hit:

20 Spots 0 Hits: 1 In 843.380 Or 0.11857057% 20
Spots 1 Hits: 1 In 86.446 Or 1.15678605% 20 Spots 2 Hits: 1 In
20.115 Or 4.97142576% 20 Spots 3 Hits: 1 In 8.009 Or 12.48637168%
20 Spots 4 Hits: 1 In 4.877 Or 20.50318987% 20 Spots 5 Hits: 1 In
4.287 Or 23.32807380% 20 Spots 6 Hits: 1 In 5.258 Or 19.01745147%
20 Spots 7 Hits: 1 In 8.826 Or 11.32954556% 20 Spots 8 Hits: 1 In
20.055 Or 4.98618021% 20 Spots 9 Hits: 1 In 61.420 Or 1.62814048%
20 Spots 10 Hits: 1 In 253.801 Or 0.39401000% 20 Spots 11 Hits: 1
In 1423.822 Or 0.07023351% 20 Spots 12 Hits: 1 In 10968.701 Or
0.00911685% 20 Spots 13 Hits: 1 In 118084.920 Or 0.00084685% 20
Spots 14 Hits: 1 In 1821881.628 Or 0.00005489% 20 Spots 15 Hits: 1
In 41751453.986 Or 0.00000240% 20 Spots 16 Hits: 1 In
1496372110.872 Or 0.00000007% 20 Spots 17 Hits: 1 In
90624035964.712 Or 0.00000000% 20 Spots 18 Hits: 1 In
10512388171906.553 Or 0.00000000% 20 Spots 19 Hits: 1 In
2946096785176811.500 Or 0.00000000% 20 Spots 20 Hits: 1 In
3535316142212173800.000 Or 0.00000000%

## Modern keno

The balldraw occurs at the "keno booth". The balldraw is typically determined by one of four devices: 1. Traditional “Rabbit Ear” blower 2. "AKV": Automated blower in which the balls are encoded, read by a computer, then sent to a computerized keno system for processing 3. Random Number Generator: An electronic number selection device approved by gaming authorities 4. “Hand Cage”: A spinning the metal ball cage which rolls the numbers into a slot where they are validated by a person"Keno runners" walk around calling, "keno!" and
offer to carry players' wagers to the keno booth for processing.
The keno runner is handed the wager payment and the “inside ticket”
(keno wager forms filled out by the customer) and takes the wager
and ticket to the keno counter for processing. The keno runner
returns with an "outside" ticket, which is the official wager
receipt. It is incumbent on the player to check the ticket for
errors before the game balldraw is drawn. Any errors not corrected
before the balldraw begins are not normally rectified and the
"outside" ticket receipt governs in any disputes.

In modern keno, players are offered the option of
playing multi-race keno, which books a keno ticket for a number of
sequential keno races up to 1000. The races must always start on
the next sequential race to be drawn. When the sequence of wagered
games is finished, the player is able to redeem any winnings within
the time constraints specified in the casino's rules booklet.

After picking wager numbers, recording them at
the keno booth and obtaining the “keno ticket” (official wager
receipt), the player watches the balldraw in progress as the spot
(number) selections light either on an electronic keno board or on
a video monitor.
Keno displays are typically found throughout the casino and
sometimes even appear on a television channel in casino hotel
rooms. Nowadays, after playing keno at a participating casino, keno
players can even take their multi-race keno tickets out of the
casino to watch the live balldraw or check historical draw results
at [www.kenousa.com] anywhere there is a computer and an Internet
connection.

In the past, a winning ticket needed to be taken
to the keno booth for collection immediately after the race results
were posted, and drawings usually took place approximately every
five or six minutes. In days of old, if the player tried to redeem
a winning ticket after the next sequential race began, the ticket
was declared expired and no money was paid out even if it won.
Nowadays most casinos set their "late pay" window to accommodate
the player, however there is great variation in the published late
pay window from casino to casino. Tickets played for 21 races or
more typically offer one year for collection in most major gaming
jurisdictions. Tickets played for under 21 races have a great
disparity of late pay rules from casino to casino. Keno players are
wise to read the rules published in the host casino's keno paybook
to determine when a keno pay will expire and become uncollectible.
Gaming authorities require that all pay scales and keno rules be
posted in a prominent location in keno areas.

An embellishment of keno is “way” keno or
“combination” keno. When playing a way or combination keno ticket,
the player circles groups of numbers within the spots marked and
specifies combinations of groups which combine together to make
different "ways". For example, if a player marks four numbers, and
circles two groups of two spots each, a combination ticket could be
made in which the gambler plays one 4 spot and two 2 spots (2-2).
If an additional group of two were added and circled, the player
could play ways 1/6, 3/4 and 3/2 (2-2-2), which at $1.00 per way
would create a $7.00 per race wager. Serious keno players use great
imagination on keno tickets to make complex combinations of groups
and ways with varying numbers of spots in each group. There is
literally no limit to the way players can circle spots of like or a
differing number of spots and in the resulting “ways” they can
choose to play on a keno ticket.

As alternatives to traditional paytables which
offer the selection of 1 to 20 spots, a number of special paytables
are available and are often offered as a wager choice. For example,
with the Top/Bottom paytable the keno player does not select any
spots. Rather, the player is betting that the balldraw top 40 and
bottom 40 ball distribution will be uneven. Top/Bottom typically
begins paying on a 7/13 or 13/7 ball distribution between the top
half (1 to 40) and bottom half (41 to 80) of the keno grid and the
payouts increase with each higher balldraw distribution disparity.
The same principle is applied for the Left/Right or Odd/Even
paytables. Other specialty paytables are Top Only, Bottom Only,
Left Only, Right Only, Odd Only, Even Only, Parlay, Exacta, Edge,
Square, or eXtra Million, which is proprietary to XpertX Keno
Systems. However the traditional 1 though 20 spot pick is by far
the most popular variety of live keno.

Lottery versions of keno are now used in many
National Lotteries or state licensed Lotteries around the world.
The games have different formulas depending on the wanted price
structure and whether the game is slow (daily or weekly), or if it
is a fast game with just minutes between the draws. The drawn
numbers are typically published on TV for the slow games and on
monitors at the point of sale for the fast games. A video keno
machine sometimes has a greater customer edge than a traditional
keno game. However, because live keno payouts are configurable at
will by the host casino, some live keno paytables house hold
percentages match or are even lower those for video keno machines,
which almost always have fixed paytables that don't change.

## Detailed mathematical analysis

The version of Keno played in Maryland serves as a case study in the precise calculation of win probabilities and expected return—the latter referring to the result to be realized in the long run from each unit invested.In Maryland, anyone may play keno at any of
thousands of establishments that are wired with a television screen
and an impossible-to-overlook, hot pink machine resembling a cash
register. The player uses a pencil to complete a small slip; the
attendant feeds the slip to the machine, which generates a
computer-printed ticket that is protected from tampering via
cryptographic checksum. Games—which are played every four
minutes or so—can be viewed over the accompanying
television monitor. The computer selects twenty numbers between one
and eighty. The payout is calculated based upon how many numbers
were chosen and how many were matched. Intriguingly, for the
nine-spot and ten-spot games, there is a payout if the player fails
to match any numbers—it obviously being an unusual event
for zero of nine or ten selected numbers to match any of the twenty
"dealt," so to speak, from the pool of eighty.

The probability that k of the n numbers chosen by
the player, i.e.,

- P_n (k)

occur in the twenty numbers chosen by the
computer can straightforwardly be derived:

1. The number of possible outcomes equals the
number of combinations of eighty numbers taken twenty at a
time.

2. The number of ways in which k of the n numbers
selected by the player occur in the twenty numbers selected
(putatively at random) by the central Keno computer is equal to the
number of ways in which k numbers can be chosen from a set of n
numbers.

3. The number of ways in which the remainder of
the numbers do not occur in the twenty numbers selected is given by
the number of ways in which 20-k numbers can be chosen from a set
of 80-n numbers.

Combining the foregoing, one finds that:

- P_n (k) = \frac

The payouts for each result can be read from the
Maryland keno Web site. For the purposes of our discussion, if the
player participates in the n-spot game and ends up matching k of
the twenty numbers selected, we will refer to that payout as:

- W_n (k).

The expected payout for the n-spot game can be
determined by summing, over all values of i from one to n (from
zero to n if the game pays out in the case of zero numbers
matched), the product of the payout for that result and the
probability of occurrence of that result:

\sum\limits_^P_n (i) W_n (i)

which could alternatively be represented as the
inner
product ("dot product")
of the vector of probabilities and the vector of payouts.

One finds that the best game for the player is
the three-spot game, which realizes an expected return of
approximately 62 cents for every dollar invested, or approximately
a 38% loss. The seven-spot game ranks close behind, returning just
over 60 cents per dollar. Perhaps not surprisingly, despite the
astonishingly high payoff for strong performance, the ten-spot game
is by far the poorest from the player's perspective.

## References

keno in German: Keno (Glücksspiel)

keno in Spanish: Keno

keno in Esperanto: Keno

keno in French: Keno

keno in Italian: Keno

keno in Japanese: キノ

keno in Norwegian: Keno

keno in Polish: Keno

keno in Swedish: Keno

# Synonyms, Antonyms and Related Words

bingo,
card games, chuck and toss, chuck farthing, chuck-a-luck, class
lottery, crack-loo, crap game, crap shooting, craps, draft lottery, drawing, fan-tan, grab bag,
hazard, horse racing,
interest lottery, lottery, lotto, number lottery, numbers
pool, pinball, pitch and
toss, policy, raffle, rouge et noir, roulette, shell game, sweep, sweepstake, sweepstakes, the numbers,
the numbers game, tombola, tontine,
trente-et-quarante