ROI (Return on Investment)

Return on investment, or ROI, is a percentage that expresses how much profit or loss a bettor has generated relative to the total amount they have wagered. It is calculated by dividing net profit by total stakes and multiplying by 100. ROI provides a standardized way to evaluate betting performance that accounts for volume, making it far more informative than looking at raw dollar amounts alone. A bettor who has profited $500 from $50,000 in total wagers (1% ROI) is in a very different position than one who has profited $500 from $5,000 in wagers (10% ROI), even though the dollar figure is identical.

In sports betting, a sustained positive ROI over a meaningful sample size is the clearest evidence of a profitable approach. Professional bettors often target an ROI in the range of 2% to 5% over thousands of bets, which may sound modest but translates into substantial income when applied to high volume. Recreational bettors sometimes dismiss these figures as too small, but the compounding effect of a consistent edge over large volumes is what separates long-term winners from the majority who lose.

Example

Over a football season, a bettor places 200 bets with an average stake of $100, for a total wagered amount of $20,000. At the end of the season, their bankroll has increased by $600. Their ROI is calculated as: ($600 / $20,000) x 100 = 3%. This means that for every dollar wagered, the bettor earned three cents in profit on average. While 3% may appear small on a per-bet basis, it represents a solid and sustainable edge. If the same bettor increases their volume to 1,000 bets per season at the same average stake and maintains the same ROI, their profit rises to $3,000.

Key Points

• Volume-adjusted metric: ROI normalizes performance across different bet sizes and numbers of wagers, allowing fair comparison between bettors or strategies with different levels of activity.
• Realistic expectations: Long-term ROI for skilled sports bettors typically falls between 2% and 7%. Claims of 20% or higher ROI over large samples should be treated with skepticism.
• Sample size matters: ROI calculated from 50 bets is essentially meaningless as a predictor of future performance. Hundreds or thousands of bets are needed for the figure to stabilize and become reliable.
• Affected by odds range: Bettors who primarily wager on heavy favorites will tend to show lower ROI figures than those who bet on underdogs, even if both have the same expected value, because favorite bettors turn over more money per unit of profit.
• Useful for strategy comparison: ROI allows bettors to compare the efficiency of different approaches, such as betting totals versus spreads, or one sport versus another, on equal footing.