Bankroll Management
Your bankroll is your operating capital. Without discipline here, even a genuine edge gets destroyed by variance and bad sizing.
Kelly Criterion Calculator
The Kelly Criterion tells you the mathematically optimal fraction of your bankroll to bet, given your edge and the odds. Enter your edge (how much better your true probability is vs. implied) to see recommended bet sizes.
Most recreational bettors should use Half Kelly or flat 2%, not Full Kelly. Full Kelly requires an accurately estimated edge—which is hard.
The Core Principles
Every successful sports bettor treats their bankroll like a business. These principles are non-negotiable:
- Never risk more than 2–3% per bet. At 2%, you need 50 consecutive losses to go broke—which is nearly impossible if you're betting selectively. At 10% units, a 10-game losing streak (very normal in betting) drops you to 35% of your starting bankroll.
- Separate your betting bankroll from your life money. Only bet with money you've allocated specifically for this purpose. This removes emotional decision-making from losses.
- Track every single bet. Date, game, side, odds, stake, result. Without data, you cannot know if your edge is real or if you've been on a lucky run.
- Unit size is a percentage, not a dollar amount. Your unit grows and shrinks with your bankroll. As your roll grows, so do your bets. As it shrinks, so do your bets. This is how you protect capital during losing streaks.
Fixed Unit Sizing
The simplest approach: bet the same dollar amount (e.g., $50) on every play regardless of confidence level. Works well for bettors who don't trust their ability to grade their own edge.
Pros: Easy to track. No overthinking. Consistent exposure.
Cons: Doesn't account for varying edge. A 3-unit edge play and a 1-unit play get the same bet.
Proportional / Kelly Sizing
Bet a percentage of bankroll based on your calculated edge. Kelly maximizes long-run growth rate but requires accurate edge estimation. Most pros use Half Kelly to reduce variance.
Pros: Mathematically optimal growth. Bet more when edge is bigger.
Cons: Requires knowing your true edge, which is hard. Full Kelly has severe drawdowns.
🚫 Never Chase Losses
"Chasing" means increasing your bet size after a loss to win money back faster. This is how recreational bettors blow up their bankrolls. Variance doesn't owe you a win. A losing streak of 8 or 10 bets is completely normal even for sharp bettors on good plays.
Set your unit size once. Review it monthly, not after each loss. If you feel the urge to bet 3x your normal amount after a bad day, log off and come back tomorrow. There will always be more games.
Bankroll Growth: Realistic Expectations
Professional sports bettors with genuine edges typically return 3–8% ROI over large sample sizes. That's not 3% per bet—it's 3% on total dollars wagered. Here's what that looks like:
- $1,000 bankroll, $50 units, 200 bets/year at 5% ROI = $500 profit
- $5,000 bankroll, $100 units, 500 bets/year at 4% ROI = $2,000 profit
- $10,000 bankroll, $200 units, 500 bets/year at 5% ROI = $5,000 profit
The edge compounds. After a profitable year, your unit size grows with your bankroll. Discipline during losing streaks is what separates people who cash out winners from those who give it all back.