This question was posted in mathematical newsgroups (*alt.math.recreational, alt.math.undergrad, alt.sci.math.probability*): * "Winning and Quitting on Red/Black in Roulette"*.

On the surface, the best probability for the roulette player to be ahead is in one trial (spin): 48.6% to win (versus 51.4% to lose), as far as even-money betting is concerned. I don't agree that it is the best strategy (betting all your bankroll on one spin).

Theoretically, no bankroll will put a player *ahead guaranteed*, IF flat-betting and playing very long consecutive sessions. There are moments, however, when the roulette player can be ahead by at least one betting unit. Even in even-money bets, the player has a good chance to be ahead by at least one unit after 5, or 10, or even 100 spins. But more than 20 spins are NOT recommended; the probability (odds) to lose go(es) above 50%! Think about it!

The main thing, mathematically, is the number of player's wins in N trials. To be ahead, means the player has won at least one more roulette spin (number of successes) than the number of losses in N trials. The question then becomes:

**"What are the probabilities for the player to be ahead in various numbers of trials?"**

Everybody can use my probability software **SuperFormula**, option *L: At Least M successes in N trials*.

Winning probability: p = 18/37; M must be at least (N/2) + 1.

Here is a number of cases from the player's perspective.

The figures are applicable to all even money roulette bets: black or red; even or odd; low or high (1-18 or 19-36).

1 trial (spin)

- probability (odds) to win: 48.6%; odds = 1 in 2.05

- probability (odds) to lose: 51.4%; odds = 1 in 1.95

(the probability to lose is 19/37; adding zero to unfavorable cases).

2 trials (spins)

- probability (odds) to win 2 of 2: 23.7% (1 of 2 doesn't mean 'being ahead')

- probability (odds) to lose 1 of 2: 76.3%

3 spins

- probability (odds) to win at least 2 of 3: 48%

- probability (odds) to lose at least 2 of 3: 52%

10 spins

- probability (odds) to win at least 6 of 10: 34.4%; odds = 1 in 2.91

- probability (odds) to lose at least 6 of 10: 41.1%; odds = 1 in 2.43

20 spins

- probability (odds) to win at least 11 of 20: 36.5%

- probability (odds) to lose at least 11 of 20: 46.2%

100 spins

- probability (odds) to win at least 51 of 100: 35.5%; odds = 1 in 2.82

- probability (odds) to lose at least 51 of 100: 56.8%; odds = 1 in 1.76.

It's getting worse for the player...

The *roulette strategy* (or system) is a totally different ball game! But there are professional gamblers out there, including roulette players! They must have strategies, some *roulette systems* deduced from some figures like the ones above! The player can be ahead at any point in the game. If so, maybe it's time to move to another (or casino) table: It improves the odds of winning!

Always keep track of the *losing* and *winning* streaks. Be strong and put an end to a winning streak. You are ahead, you quit the roulette table. Go to another table and wait until you are ahead. The bankroll is of the essence: It must assure going through long losing streaks. Divide the streaks in 10 spins or 20 spins. Never fight aggressively short or mid-term losing streaks. This is the best approach for those who do not know Ion Saliu's casino gambling systems. A good approach to gambling is the next best thing to a good gambling system! Applicable to blackjack and baccarat, too!
**
**

Various odds (probabilities) at 0 and 00 roulette Type of Bet Single 0 Double 0 - straight-up (1 number): 1 in 37 1 in 38 - split (2 numbers): 1 in 18.5 1 in 19 - street (3 numbers): 1 in 12.3 1 in 12.7 - corner (4 numbers): 1 in 9.25 1 in 9.5 - fiveline (5 numbers): 1 in 7.4 1 in 7.6 - sixline (6 numbers): 1 in 6.2 1 in 6.3 - column (12 numbers): 1 in 3.1 1 in 3.2 - dozen (12 numbers): 1 in 3.1 1 in 3.2 - black/red (18 numbers): 1 in 2.06 1 in 2.11 - even/odd (18 numbers): 1 in 2.06 1 in 2.11 - low/high (18 numbers): 1 in 2.06 1 in 2.11

Axiomatic one, everybody knows that the casinos have an *edge* or *house advantage (HA)* in all the games they offer, roulette including. The *house advantage* is created by the *payouts* in rapport to *total possibilities* for the respective *bet*. We can apply this simple formula based on *units paid UP* over *total possibilities TP*:

(always expressed as a percentage.)

For example, in *single-zero* roulette, the *one-number (straight-up) bet* has payout of *35 to 1*. The *to* qualifier is very important: the casino pays you 35 units and they give you back the unit you bet; thus, you get 36 units. There are *37* possibilities in *single-zero* roulette: *36* numbers from 1 to 36 plus the *0* number. Therefore, *HA = 1 – (UP / TP) = 1 – (36 / 37) = 1 – 0.973 = 0.027 = 2.7%*.

Let's calculate *HA* for the *1 to 1* bets: *black/red, even/odd, low/high*. *HA = 1 – (UP / TP) = 1 – (2 / 2.055) = 1 – 0.973 = 0.027 = 2.7%*. There are little differences among bets depending on how many decimal points we work with in our calculations.

The point is, the casinos have an advantage, or the players have a disadvantage. Nonetheless, the players' disadvantage is far better than what they face in state-run lotteries. Yet, most casino gamblers lose big, including at roulette tables. They do not have sufficient bankrolls to withstand long losing streaks.

However, around 45% of the roulette numbers lead the gamblers to profits in a few thousand spins. That is, with a sufficient bankroll, a player has a pretty good chance to make a profit, even if playing a random roulette number, or a favorite number. I analyzed about 8000 roulette spins from *Hamburg Spielbank* (casino). Quite a few numbers ended up making a profit: * roulette systems, magic numbers*.

By contrast, the more lottery drawings a player plays, the higher the degree of certainty of a loss. Let's make a comparative analysis to the roulette long series above (spins: total roulette numbers, 37, multiplied by 200). If playing the *pick-3 lottery* for some 100,000 drawings, it is guaranteed that all pick-3 straight sets will be losers. Some numbers will hit up to *3% to 5%* above the norm — but that is **not** nearly enough to assure a profit. A frequency of *3% to 5%* above the norm leads to profits in roulette, however.

If you play 1 roulette number for the next 38 spins, common belief was that you expected to win once. Not! Non! Only if you play 38 numbers in 1 spin, your chance to hit the winning number is 100%. Here is an interesting table, which includes also *The Free Roulette System #1* presented at the main roulette site.

The maximum gain comes when playing 38 numbers in one spin: 36.3%. Obviously, it makes no sense to play that way because of the house advantage. On the other hand, a so-called wise gambler is more than happy to play one number at a time. What he does is simply losing *slowly!* Not only that, but losing slowly is accompanied by losing more. That cautious type of gambling is like a placebo. A roulette system such as *Free System #1* scares most gamblers. *"Play 34 or 33 numbers in one shot? I'll have a heart attack!"* In reality, the *Free Roulette System #1* offers a 28.8% advantage over playing singular numbers in long sessions. That's mathematics, and there is no heart to worry about, axiomatic one.

You can also use **SuperFormula** to calculate all kinds of probabilities and advantage percentages. The option *L — At least M successes in N trials* is a very useful gambling instrument. If you play 19 numbers in one spin, the probability to win is 50%. If you play 19 numbers in 2 consecutive spins, the probability to win *at least once* is 75%.

Editor's note

• In an apparent change of heart, the Hamburg casino (Spielbank) offers online roulette results for free. The new link is (for the time being!):

*www.spielbank-hamburg.de/spielsaal/permanenzen.php4*

• • Real-life roulette spins are also available from the Wiesbaden, Germany, Casino (Spielbank)

*www.spielbank-wiesbaden.de/DE/621/Permanenzen2.php: Wiesbaden Spielbank Permanenzen*

.**Theory, Mathematics of Roulette Systems, Strategies, Software**based on mathematics of progressions and free-for-all.**The Best-Ever Roulette Strategy, Systems***An inventory of free and outrageously priced*.**roulette systems**.**Software, Systems: Roulette Wheel Positioning, Sectors, Birthday Paradox****"Roulette System that Won Millions!"**

~ Ion Saliu's roulette theory, systems, and software were pirated by an Australian gambling group.-
.**James Bond Roulette System for Dozens, Columns** .**Roulette Systems, Threats from Casino Chairman****Anti-Gambler Advice from John Patrick, Casino Mole***extraordinaire and conspirator*..**Wizard of Odds Had High Praise For Ion Saliu's Gambling Theory**.**Casinos pay troubled individuals to intimidate intelligent gambling system authors****Download roulette, blackjack, casino gambling, systems,**.**software**