ROI Measures Return on Amount Risked
In sports betting, ROI compares profit or loss to the total amount risked. If a system risks 100 units and finishes up 5 units, the ROI is 5%. If it loses 5 units, the ROI is -5%.
This is different from win rate. A bettor can win more than half of selections and still lose money if the prices are poor.
Units Keep Stakes Comparable
Units make results easier to compare without tying performance to one person's bankroll size. One customer may treat a unit as $10 while another treats it as $100.
Unit reporting also helps show drawdowns and volatility. A record should not hide losing stretches just because the long-term number looks better.
Sample Size Still Matters
A short-term ROI can swing hard after a few results, especially at plus-money or heavy-favorite prices. Larger samples are more informative, but even large samples do not guarantee future outcomes.
The strongest use of ROI is comparison under consistent rules: same grading process, complete record, and clear time windows.
Why a Winning Record Can Lose Money
Imagine 100 hypothetical bets at -150, each risking one unit. Sixty wins earn 60 × (100 / 150) = 40 units; forty losses cost 40 units. The result is zero profit and 0% ROI despite a 60% win rate. At that price, 60% is the break-even rate before any other costs.
Compare this with 55 wins and 45 losses at +110: 55 × 1.10 - 45 = 15.50 units of profit on 100 units risked, or 15.50% ROI. The examples show why price and stake convention matter; neither record is an ESA result or a forecast.
Key Takeaway
ESA uses ROI as one performance metric among several, alongside record, units, odds, sample size, market, tier, and date range.