First you must cut out all bets that will give you the poorest payout like the five number bet. This bet covers 00, 0, 1, 2, and 3. This bet, historically, has the lowest payout of all bets.
If you can choose between playing with a European roulette wheel or the American roulette wheel, then you should always choose the European wheel. This wheel will give you a 2.63% edge over the house.
If you are looking for the safest bet to make in roulette then choose the even money outside bet on a European table.
If you are playing roulette at a casino then here are a couple other tips to keep in mind:
If you have noticed that one number is being spun more often than the others out of around 100 spins then you may have what is called a biased wheel. This is one of the only true advantages a player has against the casino.
When playing at a casino you should also pay close attention to the dealer. If you have a seasoned dealer they may have spun the roulette wheel so many times that they have begun to spin the wheel and release the ball at the same speed consistently. This means that you could potentially predict the number that the ball will land on. Closely watch the dealer for some time before you attempt to predict where the ball will land.
But the best tip to win at online roulette is this
Find a casino that offers French roulette. There aren't many of them online because casinos are frankly scared to offer it as their edge is so low that they can't make a profit on it with their overheads. The reason for this is a special rule unique to French roulette that splits the winnings between player and house when the ball lands on the green zero. Find out more about French roulette here which includes advice on the few locations you can play French roulette on the internet.
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Technically there really is a winning system
There's a curious contradiction in the casino game of roulette. With the strategy I'm about to outline, it is in theory impossible to lose: Place a bet on a fifity fifty space, red, for example. Win, and you gain a chip of profit, continue with this strategy until you lose by falling on black. When you eventually lose, put two times your bet and half (rounding up) on red once more. Repeat this until you win again then go back to placing just the one chip. The sequence of bets if you lose 6 in a row (if 6 blacks in a row appear) is 1, 3, 9, 25, 60, 150.
If you want to reduce the chances of using up all your bank roll, you can use a system that only doubles rather than doubles and a half after every loss. A good sequence that I've used for the last few weeks is 1, 3, 6, 15, 32, 80, 170. In theory you can keep doing this forever and will always beat the casino because there won't ever be an infinite sequence of blacks. You can tailor the betting sequence to your own betting preferences, whether you want high risk high return or low risk medium return etc.
Providing you have a big bankroll you will win a very large amount of cash betting that a long sequence of blacks won't arrive. Half of the time you will win 1 dollar, the other times you'll win a lot more until you reach that improbably long string of blacks and lose the initial bankroll. But if you try putting all your wins to one side you'll discover that if this string of black occurs you will have made enough in winning bets to diminish the impact of the losses. The key is to quit before this occurs so decide on a set amount of games to play and be confident your bankroll is large enough to cover any improbable strings of results. If you just play a small amount of times you'll win a very good quantity of money with a very small chance of losing.
Try out this system with play/fun money before you risk any of your own cash. Winward casino - link below - offers you free play money, as do most casinos listed on this site, and Winward accepts US players.