Flat betting is the idea that every bet you place should be for the same amount and for the same percentage of your bankroll. If you have $500 to wager on sports, no bet should ever be more than $25 (five percent of your bankroll), and ideally, it should be around $15 (three percent of your bankroll).
You will have ups and downs as a sports bettor. There will be times when you lose multiple bets in a row. If you are consistent in your wagers and have the discipline to stick to a plan, you will survive the losing streaks, and you will turn a profit during the winning streaks.