The concept of high (19-36) and low (1-18) numbers in online Roulette can be used in betting strategies, but it doesn't actually improve your chances of winning, as Roulette is a game of chance. One common approach is to alternate between high and low number bets or consistently stick to one side. Players might also use systems like the Martingale or D'Alembert, increasing their bet after losses on high or low numbers to try and recoup losses.