Some bettors will assign 1 percent of their bankroll to a unit, while others could do 2, 3 or even 5 percent. If you have a bankroll of $1,000, for example, 1 unit could be $10 or maybe $20 or even $30. If you have a bankroll of $2,000, 1 unit could be $20 or maybe even $40 or $100.