The 31-betting strategy is an approach specifically created for blackjack. It calculates your bet size using a series of numbers (usually 1-1-1-4-8-16). If you win, you double your next bet. Should you lose, then you move on to the next number in the order. The idea is to gradually increase your bankroll through tiny wins while potentially recovering losses fast with bigger wagers. Yet, it can be risky since a few losses can quickly empty your bankroll.