French roulette
"Gwendolen at the roulette table" – 1910 illustration to George Eliot's "Daniel Deronda".

Roulette is a casino game named after the French word meaning little wheel. In the game, players might choose to place bets on either a single number or a range of numbers, the colours red or black, or whether the number is odd or even.

To determine the winning number and color, a croupier spins a wheel in one direction, then spins a ball in the opposite direction around a tilted circular track running around the circumference of the wheel. The ball eventually loses momentum and falls onto the wheel and into one of 37 (in French/European roulette) or 38 (in American roulette) coloured and numbered pockets on the wheel

## History

18th century E.O. wheel with gamblers

The first form of roulette was devised in eighteenth century France. A century earlier, Blaise Pascal introduced a primitive form of roulette in the seventeenth century in his search for a perpetual motion machine. The roulette wheel is believed to be a fusion of the English wheel games Roly-Poly, Reiner, Ace of Hearts, and E.O., the Italian board games of Hoca and Biribi, and "Roulette" from an already existing French board game of that name.

The game has been played in its present form after as early as 1796 in Paris. An early description of the roulette game in its current form is found in a French novel La Roulette, ou le Jour by Jaques Lablee, which describes a roulette wheel in the Palais Royal in Paris in 1796. The description included the house pockets, "There are exactly two slots reserved for the bank, whence it derives its sole mathematical advantage." It then goes on to describe the layout with, "...two betting spaces containing the bank's two numbers, zero and double zero". The book was published in 1801. An even earlier reference to a game of this name was published in regulations for New France (Québec) in 1758, which banned the games of "dice, hoca, faro, and roulette".

The roulette wheels used in the casinos of Paris in the late 1790s had red for the single zero and black for the double zero. To avoid confusion, the colour green was selected for the zeros in roulette wheels starting in the 1800s.

In 1843, in the German spa casino town of Bad Homburg, fellow Frenchmen François and Louis Blanc introduced the single 0 style roulette wheel in order to compete against additional casinos offering the traditional wheel with single and double zero house pockets.

In a few forms of early American roulette wheels - as shown in the 1886 Hoyle gambling books, there were numbers 1 through 28, plus a single zero, a double zero, and an American Eagle. The Eagle slot, which was a symbol of American liberty, was a house slot that brought the casino additional edge. Soon, the tradition vanished and after then the wheel features only numbered slots. Existing wheels with Eagle symbols are exceedingly rare, with fewer than a half-dozen copies known to exist. Authentic Eagled wheels in excellent condition can fetch tens of thousands of dollars at auction.

According to Hoyle "the single 0, the double 0, and eagle are never bars; but when the ball falls into either of them, the banker sweeps every thing upon the table, except what might happen to be bet on either one of them, when he pays twenty-seven for one, which is the amount paid for all sums bet upon any single figure".

1800s engraving of the French roulette

In the nineteenth century, roulette spread all over Europe and the US, fitting one of the most famous and most popular casino games. When the German government abolished gambling in the 1860s, the Blanc family moved to the last legal remaining casino operation in Europe at Monte Carlo, where they established a gambling mecca for the elite of Europe. It was here that the single zero roulette wheel became the premier game, and over the years was exported around the world, except in the United States where the double zero wheel had remained dominant.

A legend says that François Blanc supposedly bargained with the satan to obtain the secrets of roulette. The legend is based on the fact that the sum of all the numbers on the roulette wheel (from 0 to 36) is 666, which is the "Number of the Beast".

Early American West Makeshift Game

In the United States, the French double zero wheel made its way up the Mississippi from New Orleans, and then westward. It was here, because of rampant cheating by both operators and gamblers, that the wheel was eventually placed on top of the table to prevent devices being hidden in the table or wheel, and the betting layout was simplified. This eventually evolved into the American style roulette game as different from the traditional French game. The American game developed in the gambling dens across the new territories where makeshift games had been set up, whereas the French game evolved with style and leisure in Monte Carlo. Notwithstanding it is the American style layout with its simplified betting and fast cash action, using either a single or double zero wheel, that now dominates in most casinos around the world.

During the first part of the twentieth century, the only casino towns of note were Monte Carlo with the traditional single zero French wheel, and Las Vegas with the American double zero wheel. In the 1970s, casinos began to flourish around the world. By 2008 there were several hundred casinos worldwide offering roulette games. The double zero wheel is found in the U.S., Canada, South America, and the Caribbean, while the single zero wheel is predominant elsewhere.

## Rules of play against a casino

Roulette with red 12 as the winner

Roulette players have a variety of betting options. Placing inside bets is either selecting the exact number of the pocket the ball will land in, or a small range of pockets based on their proximity on the layout. Players wishing to bet on the 'outside' will select bets on larger positional groupings of pockets, the pocket color, or whether the winning number is odd or even. The payout odds for each type of bet are based on its probability.

The roulette table usually imposes minimum and maximum bets, and these rules usually apply separately for all of a player's inside and outside bets for each spin. For inside bets at roulette tables, a few casinos might use separate roulette table chips of various colours to distinguish players at the table. Players can continue to place bets as the ball spins around the wheel until the dealer announces no more bets or rien ne va plus.

Croupier's rake pushing chips across a roulette layout

When a winning number and colour is determined by the roulette wheel, the dealer will place a marker, additionally known as a dolly, on that winning number on the roulette table layout. When the dolly is on the table, no players might place bets, collect bets, or remove any bets from the table. The dealer will then sweep away all additional losing bets either by hand or rake, and determine all of the payouts to the remaining inside and outside winning bets. When the dealer is finished making payouts, the marker is removed from the board where players collect their winnings and make new bets. The winning chips remain on the board.

### California Roulette

In 2004, California legalised a form of roulette known as California Roulette. By law, the game must use cards and not slots on the roulette wheel to pick the winning number. There are at least two variations. In a few casinos, the dealer spins a wheel containing 38 cards from 1 to 36, plus 0 and 00, and after betting is closed, stops the wheel; a pointer identifies the winning card, which the dealer removes and shows to the players. In the Cache Creek casino in northern California, a wheel resembling a traditional roulette wheel is used, but it has only alternating red and black slots with no numbers. As the ball is spinning, the dealer takes cards from a shoe and places two of them face down on the table in red and black rectangles. When the ball lands in a red or black slot, the card in the corresponding rectangle is turned over to reveal the winning number.

## Roulette wheel number sequence

The pockets of the roulette wheel are numbered from 0 to 36.

In number ranges from 1 to 10 and 19 to 28, odd numbers are red and even are black. In ranges from 1 to 18 and 29 to 36, odd numbers are black and even are red.

There is a green pocket numbered 0 (zero). In American roulette, there's a second green pocket marked 00. Pocket number order on the roulette wheel adheres to the following clockwise sequence in most casinos:

Single-zero wheel
0-32-15-19-4-21-2-25-17-34-6-27-13-36-11-30-8-23-10-5-24-16-33-1-20-14-31-9-22-18-29-7-28-12-35-3-26
Double-zero wheel
0-28-9-26-30-11-7-20-32-17-5-22-34-15-3-24-36-13-1-00-27-10-25-29-12-8-19-31-18-6-21-33-16-4-23-35-14-2

## Roulette table layout

French style layout, French single zero wheel

The cloth covered betting area on a roulette table is known as the layout. The layout is either single zero or double zero. The European style layout has a single zero, and the American style layout is usually a double zero. The American style roulette table with a wheel at one end is now used in most casinos. The French style table with a wheel in the centre and a layout on either side is rarely found outside of Monte Carlo.

## Types of bets

In roulette, bets can either be inside or outside bets.

### Inside bets

NameDescriptionChip placement
Straight/SingleBet on a single numberEntirely within the square for the chosen number
SplitBet on two vertically/horizontally adjacent numbers (e.g. 14-17 or 8-9)On the edge shared by the numbers
StreetBet on three consecutive numbers in a horizontal line (e.g. 7-8-9)On the outer edge of the number at either end of the line
Corner/SquareBet on four numbers that meet at one corner (e.g. 10-11-13-14)On the common corner
Six Line/Double StreetBet on six consecutive numbers that form two horizontal lines (e.g. 31-32-33-34-35-36)On the outer corner shared by the two leftmost or the two rightmost numbers
TrioA three-number bet that involves at least one zero: 0-1-2 (either layout); 0-2-3 (single-zero only); 0-00-2 or 00-2-3 (double-zero only)On the corner shared by the three chosen numbers
Basket/First FourBet on 0-1-2-3 (Single-zero layout only)On the outer corner shared by 0-1 or 0-3
Top LineBet on 0-00-1-2-3 (Double-zero layout only)On the outer corner shared by 0-1 or 00-3

### Outside bets

Outside bets typically have smaller payouts with better odds at winning. Except as noted, all of these bets lose if a zero comes up.

1 to 18 (Low or Manque), or 19 to 36 (High or Passe)
A bet that the number will be in the chosen range.
Red or black (Rouge ou Noir)
A bet that the number will be the chosen color.
Even or odd (Pair ou Impair)
A bet that the number will be of the chosen type.
Dozen bet
A bet that the number will be in the chosen dozen: first (1-12, Premiere douzaine or P12), second (13-24, Moyenne douzaine or M12), or third (25-36, Dernière douzaine or D12).
Column bet
A bet that the number will be in the chosen vertical column of 12 numbers, such as 1-4-7-10 on down to 34. The chip is placed on the space below the final number in this sequence.
Snake Bet
A special bet that covers the numbers 1, 5, 9, 12, 14, 16, 19, 23, 27, 30, 32, and 34. It has the same payout as the dozen bet and takes its name from the zigzagging, snakelike pattern traced out by these numbers. The snake bet isn't available in all casinos; when it is allowed, the chip is placed on the lower corner of the 34 square that borders the 19-36 betting box. Some layouts mark the bet with a two-headed snake that winds from 1 to 34, and the bet can be placed on the head at either end of the body.

In the United Kingdom, the farthest outside bets (low/high, red/black, even/odd) result in the player losing only half of their bet if a zero comes up.

## Bet odds table

The payout (except for the special case of Top line bets), for American and European roulette, can be calculated by:

${displaystyle mathrm {payout} ={frac {1}{n}}(36-n)={frac {36}{n}}-1}$

where n is the number of squares the player is betting on. The initial bet is returned in addition to the mentioned payout. It can be easily demonstrated that this payout formula would lead to a zero expected value of profit if there were only 36 numbers. Having 37 or 38 numbers gives the casino its edge.

Bet nameWinning spacesPayoutOdds against winning (French)Expected value
(on a \$1 bet) (French)
Odds against winning (American)Expected value
(on a \$1 bet) (American)
0035 to 136 to 1−\$0.02737 to 1−\$0.053
000035 to 137 to 1−\$0.053
Straight upAny single number35 to 136 to 1−\$0.02737 to 1−\$0.053
Row0, 0017 to 118 to 1−\$0.053
Splitany two adjoining numbers vertical or horizontal17 to 117 12 to 1−\$0.02718 to 1−\$0.053
Streetany three numbers horizontal (1, 2, 3 or 4, 5, 6, etc.)11 to 111 13 to 1−\$0.02711 23 to 1−\$0.053
Cornerany four adjoining numbers in a block (1, 2, 4, 5 or 17, 18, 20, 21, etc.)8 to 18 14 to 1−\$0.0278 12 to 1−\$0.053
Top line or Basket0, 00, 1, 2, 36 to 16 35 to 1−\$0.079
Six lineany six numbers from two horizontal rows (1, 2, 3, 4, 5, 6 or 28, 29, 30, 31, 32, 33 etc.)5 to 15 16 to 1−\$0.0275 13 to 1−\$0.053
1st column1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 342 to 12 112 to 1−\$0.0272 16 to 1−\$0.053
2nd column2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 352 to 12 112 to 1−\$0.0272 16 to 1−\$0.053
3rd column3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 362 to 12 112 to 1−\$0.0272 16 to 1−\$0.053
1st dozen1 through 122 to 12 112 to 1−\$0.0272 16 to 1−\$0.053
2nd dozen13 through 242 to 12 112 to 1−\$0.0272 16 to 1−\$0.053
3rd dozen25 through 362 to 12 112 to 1−\$0.0272 16 to 1−\$0.053
Odd1, 3, 5, ..., 351 to 11 118 to 1−\$0.0271 19 to 1−\$0.053
Even2, 4, 6, ..., 361 to 11 118 to 1−\$0.0271 19 to 1−\$0.053
Red1, 3, 5, 7, 9, 12,
14, 16, 18, 19, 21, 23,
25, 27, 30, 32, 34, 36
1 to 11 118 to 1−\$0.0271 19 to 1−\$0.053
Black2, 4, 6, 8, 10, 11,
13, 15, 17, 20, 22, 24,
26, 28, 29, 31, 33, 35
1 to 11 118 to 1−\$0.0271 19 to 1−\$0.053
1 to 181, 2, 3, ..., 181 to 11 118 to 1−\$0.0271 19 to 1−\$0.053
19 to 3619, 20, 21, ..., 361 to 11 118 to 1−\$0.0271 19 to 1−\$0.053

Note that Top line (0, 00, 1, 2, 3) has a different expected value because of approximation of the correct 6 15-to-1 payout obtained by the formula to 6-to-1. Note additionally that 0 and 00 aren't odd or even, or high or low.

En prison rules, when used, reduce the house advantage.

## House edge

The house average or house edge or house advantage (also called the expected value) is the amount the player loses relative for any bet made, on average. If a player bets on a single number in the American game there's a probability of 138 that the player wins 35 times the bet, and a 3738 chance that the player loses his bet. The expected value is:

−1 × 3738 + 35 × 138 = −0.0526 (5.26% house edge)

For European roulette, a single number wins 137 and loses 3637:

−1 × 3637 + 35 × 137 = −0.0270 (2.70% house edge)

The presence of the green squares on the roulette wheel and on the table is technically the only house edge. Outside bets will always lose when a single or double zero comes up. Notwithstanding the house additionally has an edge on inside bets because the pay outs are always set at 35 to 1 when you mathematically have a 1 out of 38 (1 out of 37 for French/European roulette) chance at winning a straight bet on a single number. To demonstrate the house edge on inside bets, imagine placing straight \$1 wagers on all inside numbers (including 0 and 00) to guarantee a win: you would only get back \$36, having spent \$38. The only exceptions are the five numbers bet where the house edge is considerably higher (7.89% on an American wheel), and the "even money" bets in a few European games (French Roulette) where the house edge is halved because only half the stake is lost when a zero comes up. This is commonly called the "la partage" rule, and it is considered being the main difference of European and French roulette. There is additionally modification of this rule, which is called "en prison" rule. These rules cut the house edge into half (1.35%) in French roulette, when playing even-money bets, as half of the even-money bets are given back for player if the zero is draw in the wheel.

The house edge shouldn't be confused with the "hold". The hold is the average percentage of the money originally brought to the table that the player loses before he leaves—the actual "win" amount for the casino. The Casino Control Commission in Atlantic City releases a monthly report showing the win/hold amounts for each casino. The average win/hold for double zero wheels is between 21–30%, significantly more than the 5.26% house edge. This reflects the fact that the player is churning the same money over and over again. A 23.6% hold, for example, would imply that, on average, the player bets the total he brought to the table five times, as 23.6% is approximately equal to 100% − (100% − 5.26%)5. For example, a player with \$100 making \$10 bets on red (which has a near 50/50 chance of winning) is highly unlikely to lose all his money after only 10 bets, and will most likely continue to bet until he has lost all of his money or decides to leave. A player making \$10 bets on a single number (with only 1/38 chance of success) with a \$100 bankroll is far more likely to lose all of his money after only 10 bets.

In the early frontier gambling saloons, the house would set the odds on roulette tables at 27 for 1. This meant that on a \$1 bet you would get \$27 and the house would keep your initial dollar. Today most casino odds are set by law, and they have to be either 34 to 1 or 35 to 1. This means that the house pays you \$34 or \$35 and you get to keep your original \$1 bet.

## Mathematical model

As an example, we can examine the European roulette model, that is,roulette with only one zero. Since this roulette has 37 cells with equal odds of hitting, this is a final model of field probability ${displaystyle (Omega ,2^{Omega },mathbb {P} )}$, where ${displaystyle Omega ={0,ldots ,36}}$, ${displaystyle mathbb {P} (A)={frac {|A|}{37}}}$ for all ${displaystyle Ain 2^{Omega }}$.

Call the bet ${displaystyle S}$ a triple ${displaystyle (A,r,xi )}$, where ${displaystyle A}$ is the set of chosen numbers, ${displaystyle rin mathbb {R} _{+}}$ is the size of the bet, and, and ${displaystyle xi :Omega to mathbb {R} }$ determines the return of the bet.

The rules of European roulette have 10 types of bets. First we can examine the 'Straight Up' bet. In this case, ${displaystyle S=({omega _{0}},r,xi )}$, for a few ${displaystyle omega _{0}in Omega }$, and ${displaystyle xi }$ is determined by

${displaystyle xi (omega )={begin{cases}-r,&omega neq omega _{0}35cdot r,&omega =omega _{0}end{cases}}.}$

The bet's expected net return, or profitability, is equal to

${displaystyle M[xi ]={frac {1}{37}}sum _{omega in Omega }xi (omega )={frac {1}{37}}left(xi (omega ^{prime })+sum _{omega neq omega ^{prime }}xi (omega )right)={frac {1}{37}}left(35cdot r-36cdot rright)=-{frac {r}{37}}approx -0.027r.}$

Without details, for a bet, black (or red), the rule is determined as

${displaystyle xi (omega )={begin{cases}-r,&omega {text{ is red}}-r,&omega =0r,&omega {text{ is black}}end{cases}},}$

and the profitability

${displaystyle M[xi ]={frac {1}{37}}(18cdot r-18cdot r-r)=-{frac {r}{37}}}$.

For similar reasons it is simple to see that the profitability is additionally equal for all remaining types of bets. ${displaystyle -{frac {r}{37}}}$.

In reality this means that, the more bets a player makes, the more he's going to lose independent of the strategies (combinations of bet types or size of bets) that he employs:

${displaystyle sum _{n=1}^{infty }M[xi _{n}]=-{frac {1}{37}}sum _{n=1}^{infty }r_{n}to -infty .}$

Here, the profit margin for the roulette owner is equal to approximately 2.7%. Nevertheless, several roulette strategy systems have been developed notwithstanding the losing odds. These systems can not change the odds of the game in favour of the player.

It is worth noting that the odds for the player in American roulette are even worse, as the bet profitability is at worst ${displaystyle -{frac {3}{38}}rapprox -0.0789r}$, and never better than ${displaystyle -{frac {r}{19}}approx -0.0526r}$.

### Simplified mathematical model

For a roulette wheel with n green numbers and 36 additional unique numbers the chance of the ball landing on a given number is ${displaystyle {frac {1}{(36+n)}}}$. For a betting option with p numbers that define a win, the chance of winning a bet is ${displaystyle {frac {p}{(36+n)}}}$

For example, betting on "red", there are 18 red numbers, ${displaystyle p=18}$, the chance of winning is ${displaystyle {frac {18}{(36+n)}}}$.

The payout given by the casino for a win is based on the roulette wheel having 36 outcomes and the payout for a bet is given by ${displaystyle {frac {36}{p}}}$ .

For example, betting on 1-12 there are 12 numbers that define a win, ${displaystyle p=12}$, the payout is ${displaystyle {frac {36}{12}}=3}$, so the better wins 3 times their bet.

The average return on a player’s bet is given by ${displaystyle {frac {p}{(36+n)}}times {frac {36}{p}}={frac {36}{(36+n)}}}$

For ${displaystyle n>0}$ the average return is always lower than 1 so on average a player will lose money. With 1 green number ${displaystyle n=1}$ the average return is ${displaystyle {frac {36}{37}}}$, that is, after a bet the player will on average have ${displaystyle {frac {36}{37}}}$ of their original bet returned to them. With 2 green numbers ${displaystyle n=2}$ the average return is ${displaystyle {frac {36}{38}}}$.

This shows that the expected return is independent of the choice of bet.

## Called (or call) bets or announced bets

Although most often named "call bets" technically these bets are more accurately referred to as "announced bets". The legal distinction between a "call bet" and an "announced bet" is that a "call bet" is a bet called by the player without him placing any money on the table to cover the cost of the bet. In a large number of jurisdictions (most notably the United Kingdom) this is considered gambling on credit and is illegal in a few jurisdictions around the world. An "announced bet" is a bet called by the player for which he immediately places enough money to cover the amount of the bet on the table, prior to the outcome of the spin or hand in progress being known.

There are different number series in roulette that have special names attached to them. Most commonly these bets are known as "the French bets" and each covers a section of the wheel. For the sake of accuracy, zero spiel although explained below isn't a French bet, it is more accurately "the German bet". Players at a table might bet a set amount per series (or multiples of that amount). The series are based on the way certain numbers lie next to each additional on the roulette wheel. Not all casinos offer these bets, and a few might offer additional bets or variations on these.

### Voisins du zéro (neighbors of zero)

This is a name, more accurately "grands voisins du zéro", for the seventeen numbers which lie between 22 and 25 on the wheel including 22 and 25 themselves. The series is 22-18-29-7-28-12-35-3-26-0-32-15-19-4-21-2-25 (on a single zero wheel).

Nine chips or multiples thereof are bet. Two chips are placed on the 0-2-3 trio; one on the 4-7 split; one on 12-15; one on 18-21; one on 19-22; two on the 25-26-28-29 corner; and one on 32-35.

### Jeu zéro (zero game)

Zero game, additionally known as zero spiel (Spiel is German for game or play), is the name for the numbers closest to zero. All numbers in the zero game are included in the voisins, but are placed differently. The numbers bet on are 12-35-3-26-0-32-15.

The bet consists of four chips or multiples thereof. Three chips are bet on splits and one chip straight-up: one chip on 0-3 split, one on 12-15 split, one on 32-35 split and one straight-up on number 26.

This type of bet is popular in Germany and a large number of European casinos. It is additionally offered as a 5-chip bet in a large number of Eastern European casinos. As a 5-chip bet it is known as "zero spiel naca" and includes, in addition to the chips placed as noted above, a straight-up on number 19.

### Le tiers du cylindre (third of the wheel)

This is the name for the twelve numbers which lie on the opposite side of the wheel between 27 and 33 including 27 and 33 themselves. On a single-zero wheel, the series is 27-13-36-11-30-8-23-10-5-24-16-33. The full name (although quite rarely used—most players refer to it as "tiers") for this bet is "le tiers du cylindre" (translated from French into English meaning one third of the wheel) because it covers twelve numbers (placed as six splits), which is as close to 13 of the wheel as one can get.

Very popular in British casinos, tiers bets outnumber voisins and orphelins bets by a massive margin.

Six chips or multiples thereof are bet. One chip is placed on each of the following splits: 5-8; 10-11; 13-16; 23-24; 27-30; 33-36.

The tiers bet is additionally called the "small series" and in a few casinos (most notably in South Africa) "series 5-8".

A variant known as "tiers 5-8-10-11" has an additional chip placed straight up on 5, 8, 10 and 11; and so is a 10-piece bet. In a few places the variant is called "gioco Ferrari" with a straight up on 8, 11, 23 and 30; the bet is marked with a red G on the racetrack.

### Orphelins (orphans)

These numbers make up the two slices of the wheel outside the tiers and voisins. They contain a total of eight numbers, comprising 17-34-6 and 1-20-14-31-9.

Five chips or multiples thereof are bet on four splits and a straight-up: one chip is placed straight-up on 1 and one chip on each of the splits: 6-9; 14-17; 17-20 and 31-34.

### ... and the neighbors

A number might be backed along with the two numbers on the either side of it in a 5-chip bet. For example, "0 and the neighbors" is a 5-chip bet with one piece straight-up on 3, 26, 0, 32 and 15. Neighbors bets are often put on in combinations, for example "1, 9, 14 and the neighbors" is a 15-chip bet covering 18, 22, 33, 16 with one chip; 9, 31, 20, 1 with two chips and 14 with three chips.

Any of the above bets might be combined, e.g. "orphelins by 1 and zero and the neighbours by 1". The "...and the neighbors" is often assumed by the croupier.

### Final bets

Another bet offered on the single zero game is "final", "finale" or "finals".

Final 4, for example, is a 4-chip bet and consists of one chip placed on each of the numbers ending in 4, that's 4, 14, 24 and 34. Final 7 is a 3-chip bet, one chip each on 7, 17 and 27. Final bets from final 0 (zero) to final 6 cost four chips. Final bets 7, 8 and 9 cost three chips.

Some casinos additionally offer split-final bets, for example final 5-8 would be a 4-chip bet, one chip each on the splits 5-8, 15-18, 25-28 and one on 35.

### Full completes/maximums

A complete bet places all of the inside bets on a certain number. Full complete bets are most often bet by high rollers as maximum bets.

The maximum amount allowed to be wagered on a single bet in European roulette is based on a progressive betting model. If the casino allows a maximum bet of \$1000 on a 35-to-1 straight-up, then on each 17-to-1 split connected to that straight-up, \$2000 might be wagered. Each 8-to-1 corner that covers four numbers) might have \$4000 wagered on it. Each 11-to-1 street that covers three numbers might have \$3000 wagered on it. Each 5-to-1 six-line might have \$6000 wagered on it. Each \$1000 incremental bet would be represented by a marker that's used to specifically identify the player and the amount bet.

For instance, if a patron wished to place a full complete bet on 17, the player would call "17 to the maximum". This bet would require a total of 40 chips or \$40,000. To manually place the same wager, the player would need to bet:

17 to the maximum
Bet typeNumber(s) bet onChipsAmount waged
Straight-up171\$1,000
Split14-172\$2,000
Split16-172\$2,000
Split17-182\$2,000
Split17-202\$2,000
Street16-17-183\$3,000
Corner13-14-16-174\$4,000
Corner14-15-17-184\$4,000
Corner16-17-19-204\$4,000
Corner17-18-20-214\$4,000
Six line13-14-15-16-17-186\$6,000
Six line16-17-18-19-20-216\$6,000
Total40\$40,000

The player calls his bet to the croupier (most often after the ball has been spun) and places enough chips to cover the bet on the table within reach of the croupier. The croupier will immediately announce the bet (repeat what the player has just said), ensure that the correct monetary amount has been given while simultaneously placing a matching marker on the number on the table and the amount wagered.

The payout for this bet if the chosen number wins is 392 chips, in the case of a \$1000 straight-up maximum, \$40,000 bet, a payout of \$392,000. The player's wagered 40 chips, as with all winning bets in roulette, are still his property and in the absence of a request to the contrary are left up to possibly win again on the next spin.

Based on the location of the numbers on the layout, the number of chips required to "complete" a number can be determined.

• Zero costs 17 chips to complete and pays 235 chips.
• Number 1 and number 3 each cost 27 chips and pay 297 chips.
• Number 2 is a 36-chip bet and pays 396 chips.
• 1st column numbers 4 to 31 and third column numbers 6 to 33, cost 30 chips each to complete. The payout for a win on these 30-chip bets is 294 chips.
• 2nd column numbers 5 to 32 cost 40 chips each to complete. The payout for a win on these numbers is 392 chips.
• Numbers 34 and 36 each cost 18 chips and pay 198 chips.
• Number 35 is a 24-chip bet which pays 264 chips.

Most typically (Mayfair casinos in London and additional top class European casinos) with these maximum or full complete bets, nothing (except the aforementioned maximum button) is ever placed on the layout even in the case of a win. Experienced gaming staff, and the type of customers playing such bets, are fully aware of the payouts and so the croupier simply makes up the correct payout, announces its value to the table inspector (floor person in the U.S.) and the customer, and then passes it to the customer, but only after a verbal authorization from the inspector has been received.

Also typically at this level of play (house rules allowing) the experienced croupier caters to the needs of the customer and will most often add the customer's winning bet to the payout, as the type of player playing these bets quite rarely bets the same number two spins in succession. For example, the winning 40-chip / \$40,000 bet on "17 to the maximum" pays 392 chips / \$392,000. The experienced croupier would pay the player 432 chips / \$432,000, that's 392 + 40, with the announcement that the payout "is with your bet down".

There are additionally several methods to determine the payout should a number adjacent to a chosen number be the winner; for example, player bets 40 chips on "23 to the maximum" and number 26 is the winning number. The most notable method is known as the "station" system or method. When paying in stations, the dealer counts the number of ways or stations that the winning number hits the complete bet. In the example above, 26 hits four stations – two different corners, one split and one six-line. The dealer takes the number four, multiplies it by 30 and adds the remaining eight to the payout. 4 × 30 = 120, 120 + 8 = 128. If calculated as stations they would just multiply 4 by 36 making 144 with the players bet down.

In a few casinos, a player might bet full complete for less than the table straight-up maximum; for example, "number 17 full complete by \$25" would cost \$1000, that's 40 chips each at \$25 value.

## Betting strategies and tactics

Over the years, a large number of people have tried to beat the casino, and turn roulette—a game designed to turn a profit for the house—into one on which the player expects to win. Most of the time this comes down to the use of betting systems, strategies which say that the house edge can be beaten by simply employing a special pattern of bets, often relying on the "Gambler's fallacy", the idea that past results are any guide to the future (for example, if a roulette wheel has come up 10 times in a row on red, that red on the next spin is any more or less likely than if the last spin was black).

All betting systems that rely on patterns, when employed on casino edge games will result, on average, in the player losing money. In practice, players employing betting systems might win, and might indeed win quite large sums of money, but the losses (which, depending on the design of the betting system, might occur quite rarely) will outweigh the wins. Certain systems, such as the Martingale, described below, are extremely risky, because the worst-case scenario (which is mathematically certain to happen, at a few point) might see the player chasing losses with ever-bigger bets until he runs out of money.

The American mathematician Patrick Billingsley said that no betting system can convert a subfair game into a profitable enterprise. At least in the 1930s, a few professional gamblers were able to consistently gain an edge in roulette by seeking out rigged wheels (not difficult to find at that time) and betting opposite the largest bets.

### Prediction methods

Whereas betting systems are essentially an attempt to beat the fact that a geometric series with initial value of 0.95 (American roulette) or 0.97 (European roulette) will inevitably over time tend to zero, engineers instead attempt to overcome the house edge through predicting the mechanical performance of the wheel, most notably by Joseph Jagger at Monte Carlo in 1873. These schemes work by determining that the ball is more likely to fall at certain numbers, and if sufficiently good will raise the return of the game above 100%, defeating the betting system problem.

Edward O. Thorp (the developer of card counting and an early hedge-fund pioneer) and Claude Shannon (a mathematician and electronic engineer best known for his contributions to information theory) built the first wearable computer to predict the landing of the ball in 1961. This system worked by timing the ball and wheel, and using the information obtained to calculate the most likely octant where the ball would fall. Ironically, this technique works best with an unbiased wheel though it could still be countered quite easily by simply closing the table for betting before beginning the spin.

In 1982, several casinos in Britain began to lose large sums of money at their roulette tables to teams of gamblers from the USA. Upon investigation by the police, it was discovered they were using a legal system of biassed wheel-section betting. As a result of this, the British roulette wheel manufacturer John Huxley manufactured a roulette wheel to counteract the problem.

The new wheel, designed by George Melas, was called "low profile" because the pockets had been drastically reduced in depth, and various additional design modifications caused the ball to descend in a gradual approach to the pocket area. In 1986, when a professional gambling team headed by Billy Walters won \$3.8 million using the system on an old wheel at the Golden Nugget in Atlantic City, every casino in the world took notice, and within one year had switched to the new low-profile wheel.

Thomas Bass, in his book The Eudaemonic Pie (1985) (published as The Newtonian Casino in Britain), has claimed to be able to predict wheel performance in real time. The book describes the exploits of a group of University of California Santa Cruz students, who called themselves the Eudaemons, who in the late 1970s used computers in their shoes to win at roulette. This is an updated and improved version of Edward O Thorp's approach, where Newtonian Laws of Motion are applied to track the roulette ball's deceleration; hence the British title.

In the early 1990s, Gonzalo Garcia-Pelayo believed that casino roulette wheels weren't perfectly random, and that by recording the results and analysing them with a computer, he could gain an edge on the house by predicting that certain numbers were more likely to occur next than the 1-in-36 odds offered by the house suggested. This he did at the Casino de Madrid in Madrid, Spain, winning 600,000 euros in a single day, and one million euros in total. Legal action against him by the casino was unsuccessful, it being ruled that the casino should fix its wheel.

To prevent exploits like these, the casinos monitor the performance of their wheels, and rebalance and realign them regularly to try to keep the result of the spins as uniform as possible.

In 2004 it was reported that a group of two Serbs and one Hungarian in London had used a laser scanner hidden inside a mobile phone linked to a computer to predict the sector of the wheel where the ball was most likely to drop. They were arrested, but released without charge as there was no proof they had technically interfered with casino equipment.

### Specific betting systems

The numerous even-money bets in roulette have inspired a large number of players over the years to attempt to beat the game by using one or more variations of a martingale betting strategy, wherein the gamer doubles the bet after every loss, so that the first win would recover all previous losses, plus win a profit equal to the original bet. The problem with this strategy is that, remembering that past results don't affect the future, it is possible for the player to lose so a large number of times in a row, that the player, doubling and redoubling his bets, either runs out of money or hits the table limit. A large financial loss is certain in the long term if the player continued to employ this strategy. An Additional strategy is the Fibonacci system, where bets are calculated according to the Fibonacci sequence. Regardless of the specific progression, no such strategy can statistically overcome the casino's advantage, after the expected value of each allowed bet is negative.

While not a strategy to win money, former Los Angeles Times editor Andrés Martinez described a betting method in his book on Las Vegas titled "24/7". He called it the "dopey experiment". The idea is to divide one's roulette session bankroll into 35 units. This unit is bet on a particular number for 35 consecutive spins. Thus, if the number hits in that time, the gambler wins back the original bankroll and can play subsequent spins with house money. Notwithstanding there's only a 1 − (3738)35 = 60.68% probability of winning within 35 spins (assuming a double-zero wheel with 38 pockets).

### Labouchère system

The Labouchère System is a progression betting strategy like the martingale but doesn't require the gambler to risk his stake as quickly with dramatic double-ups. The Labouchere System involves using a series of numbers in a line to determine the bet amount, following a win or a loss. Typically, the player adds the numbers at the front and end of the line to determine the size of the next bet. When he wins, he crosses out numbers and continues working on the smaller line. If he loses, then he adds his previous bet to the end of the line and continues to work on the longer line. This is a much more flexible progression betting system and there's much room for the player to design his initial line to his own playing preference.

This system is one that's designed so that when the player has won over a third of his bets (less than the expected 18/38), he'll win. Whereas the martingale will cause ruin in the event of a long sequence of successive losses, the Labouchère system will cause bet size to grow quickly even where a losing sequence is broken by wins. This occurs because as the player loses, the average bet size in the line increases.

As with all additional betting systems, the average value of this system is negative.

### D'Alembert system

The system, additionally called montant et demontant (from French, meaning upwards and downwards), is often called a pyramid system. It is based on a mathematical equilibrium theory devised by a French mathematician of the same name. Like the martingale, this system is mainly applied to the even-money outside bets, and is favoured by players who want to keep the amount of their bets and losses to a minimum. The betting progression is quite simple: After each loss, you add one unit to the next bet, and after each win, one unit is deducted from the next bet. Starting with an initial bet of, say, 1 unit, a loss would raise the next bet to 2 units. If this is followed by a win, the next bet would be 1 units.

This betting system relies on the gambler's fallacy—that the player is more likely to lose following a win, and more likely to win following a loss.

### Other systems

There are numerous additional betting systems that rely on this fallacy, or that attempt to follow 'streaks' (looking for patterns in randomness), varying bet size accordingly.

Many betting systems are sold online, and might make outlandish promises that the player can 'beat' the system by following them. One such system was advertised by Jason Gillon of Rotherham, UK, who claimed you could 'earn £200 daily' by following his betting system, described as a 'loophole'. As the system was advertised in the UK press, it was subject to Advertising Standards Authority regulation, and following a complaint, it was ruled by the ASA that Mr. Gillon had failed to support his claims you could earn £200 daily, and that he had failed to show that there was any loophole.

### Using the dozen bet

There are two versions to this system, single-dozen bets and double-dozen bets. In the single-dozen-bet version, the player uses a progressively incrementing stake list starting from the casino table minimum, to the table maximum. The aim here is to use a single-dozen bet to win before the stake list ends. Many techniques are employed, such as betting on the same dozen to seem after two consecutive appearances, betting on the dozen that has appeared most in the last 15, 9, or 5 spins, and betting on the dozen that, after a long absence of 7 or more spins, appears for the first time. The double-dozen bet version uses two dozen bets and half the stake list size of the single-dozen-bet version.

## Real-life roulette exploits

• In 1873, Briton Joseph Jaggers made the first famous biassed roulette wheel exploit. Mr. Jaggers, with a team of six accomplices, carefully observed all the wheels at the Monte Carlo casino and found one wheel with significant bias. By taking advantage of this flaw they managed to win over \$325,000, an astronomical sum in 1873.
• In the summer of 1891 at the Monte Carlo casino, a part-time swindler and petty criminal from London named Charles Wells broke the bank at each table he played over a period of several days. Breaking the bank meant he won all the available money in the table bank that day, and a black cloth would be placed over the table until the bank was replenished. In song and life, he was celebrated as "The Man Who Broke the Bank at Monte Carlo".
• In 1992 in Gdynia (Poland) in Jackpol Casino, Paweł Piskorski (Polish politician, former Secretary General of Platforma Obywatelska and Member of European Parliament, today Leader of Stronnictwo Demokratyczne) claimed to have won 4,950,000,000 zloty (approximately \$175,000 today). This, at least, was the explanation he gave to the revenue office for his income that year. The claim is implausible, because the house maximum at that time was 1,000,000 zloty: he would have had to have won 138 times in succession, with each bet set at the house maximum. The odds of hitting a winning number 138 times in a row is approximately 1 in 5.88x10^214.
• In 2004, Ashley Revell of London sold all of his possessions, clothing included, and placed his entire net worth of US\$135,300 on red at the Plaza Hotel in Las Vegas. The ball landed on "Red 7" and Revell walked away with \$270,600.
• On 2 October 2009, Derren Brown (as part of his controversial "The Events" series) bet £5000 of a member of the public's money on a single number of a roulette wheel somewhere in Europe. This was shown live across the UK using a camera hidden in Brown's sleeve. He claimed that he would use the laws of physics to predict where the ball would end up, based upon the speed of the wheel and the ball. Brown took approximately three seconds after the wheel started spinning to place his £5000 bet on the number 8, only to see it land on 30 — just one number out. It isn't known whether any additional less successful bets were filmed but not broadcast (Brown has used, and explained, this "cherry picking" technique on at least two additional TV programmes, in coin tossing and horse racing).

## In film and television

• In the 1942 film Casablanca, Rick's Café Americain has a trick roulette wheel. Rick (played by Humphrey Bogart) uncharacteristically takes pity on a young Bulgarian refugee couple. The husband has lost most of his money at roulette, trying to win enough to bribe police captain Renault. Rick suggests the man bet on 22. After the number comes up, Rick tells him to let it all ride. He does, and wins again. Rick tells him to cash in his winnings ... and never come back.
• In season 5, episode 25 of I Love Lucy, Lucy Goes to Monte Carlo, Lucy finds a chip on the floor of the casino and tries to return it by placing it on the roulette table. The number she places it on hits. She tries to explain to the dealer that she didn't want to place the bet, but he doesn't understand and thinks she wants to let it ride. She continues to win while trying to return the money. She finally gives up and collects her winnings and hides it from Ricky in the Mertz's hotel room. When Ricky finds the money, he thinks that Fred has been embezzling it from Ricky's concert earnings.
• In the 17 February 1965 episode of the classic series, Danger Man, The Ubiquitous Mr. Lovegrove, John Drake (Patrick McGoohan) is injured in a car accident, and, hallucinates he's involved with the nefarious manager of a London casino. By placing bets on a roulette wheel - at a predetermined time - with a croupier in on the scheme - money is transferred with information without any outside bettors being aware.
• In the 22 October 1966 episode ("Odds on Evil") of the Mission: Impossible series, the IMF team uses a wearable computer (a la Thorpe and Shannon, above) to predict the outcome of each spin of the roulette wheel at a fictional casino in a European principality. The \$200,000 they win at roulette provides the stake they need to challenge the prince to a high-stakes game of Banco, in which they take the Prince for the money he was planning to use to buy arms in order to go to war against a neighbor.
• In the 1971 Western comedy Support Your Local Gunfighter, James Garner's character has a gambling addiction—he can't stop betting everything he has on a single roulette spin. He loses several times, but finally wins at the quite end.
• Near the beginning of the 1973 film The Sting, Johnny Hooker (Robert Redford) takes his share of the money conned from a numbers runner and loses nearly all of it on a single bet against a rigged roulette wheel.
• In the third part of the 1998 film Run, Lola, Run, Lola (Franka Potente) uses all her money to buy a 100-mark chip. (She is actually just short of 100 marks, but gains the sympathy of a casino employee who gives her the chip for what money she has.) She bets her single chip on 20 and wins. She lets her winnings ride on 20 and wins again, making her total winnings 129,600 marks (29,600 more than her smuggler boyfriend owed his boss, Ronnie). The odds of two consecutive wins on a European roulette wheel are exactly 1368-to-1 against.
• On season 1 of ITV1's Red or Black?, a player can win £1,000,000 by guessing either red or black on the roulette wheel.
• In the 2010 Disney Pixar film Toy Story 3, a scene featured a See 'n Say being used as a roulette wheel for gambling.
• In the 2011 film Fast Five, Don Omar and Tego Calderon play roulette and each bet their millions on red or black. The ball lands on green.
• In the 2012 film Madagascar 3: Europe's Most Wanted, the Penguins let their money ride/bet all of their money on a roulette wheel, selecting black & winning back twice as much.
• In the 2015 Tamil movie Vai Raja Vai directed by Aishwarya R. Dhanush, Gautham Karthik is being coerced to use his special power - 'premonition' to beat the Roulette table. He walks away winning against the casino by predicting the outcome in the Roulette table.

## Rules related to casino security

• Players shouldn't collect their winnings and betting chips on the outside chances until all of the winnings in the same box (e.g., all bets and winnings on 'red') have been paid. This is to avoid confusion and minimise the chance for players to steal additional players' chips.
• Players mustn't touch chips after the dealer gives the hand signal or announces "no more bets". Players aren't allowed to remove, change or add bets past this point.
• When the dealer has placed the dolly (the plastic marker used to mark the winning number) it is strictly prohibited to touch any chips on a winning chance.
• Dealers aren't allowed to take money to change for chips from a player's hand. If the player wishes to get more chips, he or she must place the money on the layout of the table.
• The use of electronic equipment, such as mobile phones and cameras, at the table is additionally prohibited.
• The only items allowed in front of a player are chips, money, drinks, and cigarettes. Bulky items such as wallets and purses or bags mustn't be on the table.

## Common etiquette practices

• Players should place chips on the board rather than tossing them. Tossed chips might displace additional bets or roll down to the "chipping machine". If the player can't reach to place a bet himself, he/she should announce the bet to the dealer. This is treated as any additional call bet.
• Changes for cash or colour chips are supposed to be done in between spins. If the dealer has time, he'll make changes throughout the spin, but he/she will most likely prioritise call bets before changes.
• All call bets are considered courtesy bets and are only placed if the dealer has time to change and place the bets. The bet is considered taken only if the dealer and the inspector dealer has repeated the bet. If the dealer doesn't take the bet, he/she will announce "no bet". To argue with the dealer about which bets have been taken is considered extremely impolite and will most likely render a warning from the inspector dealer or pit boss.
• Most casinos ban food at the table. Drinking rules vary.