The Martingale betting system in blackjack involves doubling your bet after each loss, aiming to recover previous losses with one win. You start with a small base bet, and after losing, you increase your bet to cover losses. Once you win, you return to the original bet size. While the system can provide short-term wins, it requires significant capital for losing streaks and is limited by casino table bet caps. It doesn’t change the odds of the game, so a long losing streak can result in large losses, making it a risky strategy.