ROI

ROI (return on investment) is the percentage of your total wagered amount you’ve won or lost over a tracked period. It’s the cleanest single metric for “are you winning at sports betting?” — more meaningful than raw dollar profit, because it normalizes for how much you’ve risked.

Formula

ROI = (net profit / total amount wagered) × 100

If you bet $10,000 across the season and netted $150 profit, your ROI is +1.5%. If you bet $10,000 and lost $300, your ROI is -3%.

Note: ROI uses total wagered, not bankroll. If you bet 1u ($100) on 100 different games, your wagered amount is $10,000 — even if your bankroll only ever was $5,000. ROI tracks performance per dollar risked, not per dollar in the bankroll.

What’s a good ROI?

For sports betting, the answer is “lower than you think”:

• +10–20% — extremely rare, almost certainly variance over a small sample.
• +5–10% — strong sharp performance over a meaningful sample (1,000+ bets).
• +2–5% — solid edge, sustainable long-term.
• 0–2% — slightly +EV, breaking even after vig.
• -2 to -5% — typical retail bettor; slow-bleeding the bankroll.
• -5 to -10% — square betting patterns, high vig markets.

The vig is roughly 4.5–5% on standard markets, so to be ROI-positive you have to overcome that and then some. Most retail bettors hover around -3 to -5% over the long run.

ROI vs bottom-line dollars

Two bettors:

• Bettor A bets $100K total, profits $5,000. ROI = 5%.
• Bettor B bets $1M total, profits $20,000. ROI = 2%.

Bettor B has more dollars; Bettor A has more edge per dollar. If both have the same bankroll capacity, Bettor A is the better bettor. If Bettor B has 10x the bankroll, the dollars are bigger but the math (per dollar risked) is worse.

For tracking your own performance, ROI is the better lens. Dollars are vanity; ROI is sanity.

Sample size matters

Don’t read too much into ROI from a small sample. Variance dominates the first few hundred bets. Some heuristics:

• Under 100 bets — basically noise. Your ROI tells you almost nothing about your edge.
• 100–500 bets — directional signal. If you’re at -10% you’re probably -EV; if you’re at +20% you’re probably overestimating.
• 500–1,000 bets — meaningful. Stable ROIs in this range are likely real.
• 1,000+ bets — high confidence. ROI converges to something close to your true edge.

Combining ROI with CLV

ROI tells you what happened. CLV tells you what should happen long-term. The combo: if your CLV is +1% but your ROI is -2%, you’re getting unlucky and the ROI will likely catch up. If your CLV is -1% but your ROI is +5%, you’re getting lucky and the ROI is going to regress.

Sharp bettors weight CLV heavier than ROI for in-season feedback because it converges faster. ROI is the seasonal scoreboard.