Online games use random number generators (RNGs) to ensure their odds match the payout of land-based casinos. Mathematical analysis should indicate the payout will average over time.
You can get the best results by combining betting systems with even money bets. There is no secret formula for Roulette. There are specific approaches you can try to get a rough estimate of a range of numbers, but there is absolutely no way to predict the outcome accurately using any particular Roulette formula.