The Mirror That Never Lies
Human memory is selective. We remember winning bets more clearly than losing ones. We tend to overestimate our hit rate. Without objective data, it's easy to convince yourself that you're winning when you're actually losing.
A complete betting record is the only antidote to this bias.
What Data to Record Per Bet
At a minimum, each bet should include:
| Field | Why It Matters |
|---|---|
| Date | Analyze performance by period |
| Sport / League | Know which markets you're profitable in |
| Match | Contextualize the pick |
| Market | 1X2, BTTS, over 2.5, AH... |
| Odds | To calculate ROI and detect value |
| Stake | To calculate real performance in € |
| Bookmaker | Compare performance by bookmaker |
| Result | Won, lost, void... |
| Tag | Custom category |
The more data, the more analysis you can do. But even with the basics, you can calculate what matters.
The Metrics That Matter Most
ROI (Return on Investment)
ROI = (Net Profit / Total Staked) × 100
A sustained positive ROI over time is proof you have an edge. Less than 5% is reasonable for sports betting. More than 10% with high volume is exceptional.
Yield
Similar to ROI but calculated differently depending on the region. In Spain and the UK, they are used interchangeably.
Hit Rate
Percentage of bets won. Note: a 40% hit rate can be very profitable if average odds are high (>2.50). A 70% hit rate can be ruinous if odds are low (1.30-1.40).
Why You Need Volume to Draw Conclusions
With fewer than 100 bets, results are almost random. Statistical variance is too high.
With 300-500 bets you can start to see reliable trends. With 1,000+ you have robust data.
Keep the record from day one, even if you don’t draw conclusions at first. The history you build now will be your most valuable asset in 6 months.
Oddfolio: Automatic Recording on Your Mobile
Oddfolio is designed so that recording a bet takes you less than 30 seconds. Enter odds, stake, result, and the app automatically calculates your ROI, bankroll evolution, and statistics by sport.
No spreadsheets, no manual errors, with visual graphs that show your real performance.
Conclusion
Keeping records is the foundation of every serious bettor. It doesn’t matter how much you know about football if you don’t know whether you’re profitable. Start today, record everything, and let the data guide you.