Roulette is not a 50/50 chance game. In fact, it's a game of chance where the odds are not evenly split. The outcome of each spin is determined by the random landing of the ball on a numbered pocket of the roulette wheel.
Outside bets in roulette carry the lowest risk. They cover more numbers yet the payouts are lower (1/1 for Red, Black, Odd, Even, 1 18, 19 36). These outside bets carry the best prospects for long-term wins.
While it's possible to use math and statistics to improve your odds at Roulette, it's important to keep in mind that the game is designed to favor the casino. The house edge in Roulette is typically around 2.7% for European Roulette and 5.26% for American Roulette.