The Martingale system is the most martingale and commonly used roulette strategy. Martingale concept behind it is pretty simple — you increase your bet after. In 'Double Ball Roulette' two balls are shot at the wheel. You can win as much as 1, x the bet, if both balls fall on the same number. Win more. The simplest of these strategies, all intended for gambling and gaming, was designed for a zero-sum game, that is, a game in which each side bets the same.