How to Beat Roulette

Mathematically speaking, there's no real way to beat roulette. All bets in American roulette have a 5.26% advantage for the house except for one, and that bet gives the house a 7.29% advantage.

Surrender

If you can find a casino that offers a surrender option, you can reduce the house odds a little further. (This option is sometimes available in Atlantic City casinos.) The option only applies to outside bets that pay even money, like odd/even, red/black, or high/low. If the ball lands on one of the 0's, you get half your bet back. This reduces the house edge to 2.63%.

European Roulette

European roulette has some significant differences from American roulette. The most significant difference is the number of 0's. European roulette only has one "0" instead of two, which cuts the house edge in half. So European roulette has a house advantage of 2.7%. And there's no five number bet in European roulette.

Systems

There are a number of roulette systems available, the most popular of which is the Martingale system. Con men and hucksters love to shill systems for roulette, but none of them work, really. The mathematical advantage that the house has in roulette is irrefutable fact, and no betting system changes that fact.

Biased Wheels

A biased roulette wheel could possibly provide an advantage to a player, if a player could find one and determine the actual nature of the bias. Roulette wheels are expensive and don't get replaced every couple of hours like dice or cards do. As a result, the wood and mechanical parts could theoretically develop imperfections.

The chances of actually finding and clocking a biased roulette wheel are pretty slim though. In fact, finding a biased wheel is probably more of a longshot than the five number bet. Casinos move their roulette wheels around too, so even if you find a biased wheel, it will probably not be in the same place next time you visit.

Clocking the wheel to find the imperfections is probably pretty laborious too. It would take over 2000 spins of a wheel to be remotely sure that a bias isn't just the result of coincidence or standard variation. Assuming 50 spins per hour (which is a generous estimate), it would take 40 hours of watching to see that many spins of the wheel.

And you'd never be able to find a biased wheel at any of the online casinos, since they use computerized random number generators.

Dealer Tracking

This is a similar concept to biased wheels, although the imperfection lies with the dealer and not the wheel. Theoretically some dealers release the ball at almost exactly the same speed every time. An experienced roulette player could theoretically watch at what point the dealer releases the ball and predict within a few numbers where the ball will land.

I'm not sure that dealer tracking is something I'd ever be able to do successfully, and I'm not entirely convinced you could gain an edge over the house doing it. But even if you could reduce the house edge a little bit, it might be worth trying.