The roulette probability of correctly predicting the winning number in the European variant is 1-in-37, or about 2.70%. If you play for 30 rounds, you have a 55% chance of getting the number right at least once.

Games like Blackjack, Craps, Baccarat, and Roulette give you the best odds of winning. The Wheel of Fortune and Keno give you the worst odds of winning. Table games always have better odds than slot machines.

American Roulette: In American Roulette, there are two green zero pockets. This means that there is an additional chance that your wagers will be void. It has a payout of 35/1 if you bet on it, but it essentially doubles the likelihood that all bets will lose money.

So the probability of getting a red on any single spin is 18/37 or 18/38. The probability of getting 13 in a row is (18/37)^13 or (18/38)^13, or 1:11697 or 1:16544 respectively.