Probability plays a crucial role in Roulette betting strategy as it determines the likelihood of winning and the expected value of each bet. Understanding the probability of each outcome, such as the number of pockets on a European wheel, helps players make informed decisions about which bets to place and how to allocate their bankroll. For example, knowing that the house edge is 2.7% on European Roulette, players can focus on placing bets with a lower house edge, such as outside bets like red/black or odd/even, rather than high-risk inside bets like straight-up numbers. By understanding probability, players can develop a strategy that balances risk and reward, increasing their chances of winning and minimizing their losses.