Martingale. The first and one of the most well-known sports betting and casino strategies on how to win is the martingale system. In its basic variant, each time you lose a bet, you should wager double on the next match. This way, whenever you win, you cover all your previous losses and gain money for the next bet.
There is no definitive right answer here. Some people "flat bet" the same amount each game; others believe the stronger their perceived edge or information is, the bigger the bet should be. Keeping your bets within 2-5% of your bankroll is likely more important than whether you bet the same amount every time.