ROI (Return on Investment)

Return on Investment tells you what a betting approach actually earned, once you strip away the noise of win rate and bet size. It’s calculated as net profit divided by total stakes, expressed as a percentage. Bet €1,000 across a season and finish up €80, and your ROI is 8%. That single number lets you compare a tipster who won 40% of their bets against one who won 65%, because raw win percentage means nothing without knowing the odds and the stakes behind it.

The reason ROI matters more than profit alone is that profit is meaningless without context. Winning €500 sounds good until you learn it took €50,000 in stakes to get there — an ROI of 1%, barely above break-even and easily wiped out by a bad month. Winning €500 from €2,000 staked is an ROI of 25%, a completely different level of performance from the same headline profit figure. ROI normalises results so you can judge skill rather than volume.

It’s also the only sensible way to compare strategies that operate at different stake levels or across different sample sizes. A staking plan that risks 1% of bankroll per bet and one that risks 5% will produce wildly different profit totals even with identical selections; ROI, calculated on turnover rather than bankroll, strips that variable out and shows which set of selections was actually sharper.

One thing ROI does not tell you is how reliable the result is. A strong ROI over 20 bets is closer to noise than evidence — variance dominates at small samples, especially in sports betting where a single unexpected red card or late goal swings several results. Serious bettors treat anything under a few hundred bets as provisional.

Example

Say you follow a value-betting approach on Eredivisie matches over a month, always staking €50 per selection at whatever decimal odds are available at the time you bet.

You place 40 bets across the month:

• 17 win, at an average price of 2.60
• 23 lose

Stakes: 40 × €50 = €2,000 total turnover.

Returns from winners: 17 × €50 × 2.60 = €2,210.

Net profit: €2,210 − €2,000 = €210.

ROI = €210 ÷ €2,000 = 0.105, or 10.5%.

Now compare that to a friend backing short-priced favourites in the same league, at average odds of 1.30, also staking €50 a bet across 40 selections, winning 30 of them.

Their stakes: also €2,000. Returns: 30 × €50 × 1.30 = €1,950. That’s a net loss of €50, an ROI of −2.5% — despite winning almost twice as often as you did. The higher strike rate feels better in the moment, but the odds were too short to cover the losers. This is exactly the comparison ROI is built for: it cuts through “I won more bets than you” and shows who actually made money relative to what they risked.

Key Points

• Always calculate ROI on turnover, not on bankroll: divide profit by total amount staked across all bets, not by your starting balance. Confusing the two inflates or deflates the figure and makes it useless for comparison against other bettors or tipsters.
• Demand a real sample before trusting the number: 20–30 bets can produce a flattering or damning ROI purely from variance. Treat results under roughly 200–300 bets as a work in progress, particularly at odds around 2.00 or higher where variance is larger.
• A positive ROI with a low strike rate can beat a high strike rate with a negative ROI: as the Eredivisie example shows, the odds you’re getting paid matter more than how often you win. Always check both figures together.
• Compare ROI within the same market type and odds range: an 8% ROI on football correct-score bets (long odds, high variance) is not directly comparable to an 8% ROI on tennis match-winner bets at odds of 1.50–2.00 (shorter odds, steadier returns). Match like with like.
• Account for the bookmaker’s built-in margin before judging your own edge: if the market overround is around 6-7%, an ROI of 2% means you’re beating the vig by a meaningful margin, not just breaking even. Know the margin in the markets you bet to interpret your ROI correctly.
• Track ROI separately from CLV (closing line value): a good ROI over a short run can still come from a strategy with no real long-term edge, whereas consistently beating the closing price is a stronger early signal that your process is sound, even before ROI catches up.