Total profit divided by total amount wagered, expressed as a percentage. The standard measure of betting profitability.
ROI (return on investment) in betting measures your profit relative to total amount wagered. A 5% ROI means you profit $5 for every $100 wagered over time.
ROI = (total profit / total wagered) × 100
Professional sports bettors typically achieve 2-7% long-term ROI. Prediction market ROI can be higher due to more frequent market inefficiencies but is limited by lower volume and longer resolution times.
ROI should be measured over large sample sizes (500+ bets minimum) to be statistically meaningful. Short-term ROI is dominated by variance.
ROI = (totalProfit / totalWagered) × 100%
$10,000 wagered over a season, $450 net profit. ROI = 450/10000 × 100 = 4.5%.
The average profit or loss per bet if you made the same wager thousands of times. Positive EV means long-term profit.
Bankroll TurnoverHow many times you cycle through your bankroll over a period. Higher turnover with positive edge means more total profit.
VarianceThe natural fluctuation in results around your expected value. High variance means bigger swings even with an edge.