If you don't track your bets, you don't actually know if you're winning or losing. Memory is generous to recent wins and harsh on recent losses. A real bet log is the difference between thinking you're a 56% NFL bettor and knowing you're a 49% NFL bettor. The work is small. The payoff is large.
What to log
At minimum, every bet should record:
- Date/time placed
- Sport / league
- Market type (spread, total, ML, prop, parlay, SGP, etc.)
- Specific selection (Bills -3.5, Mahomes over 2.5 TDs)
- Odds at placement (-110, +250, etc.)
- Stake
- Sportsbook used
- Closing odds (added after market closes)
- CLV (computed: difference between your odds and closing)
- Outcome (W/L/Push/Void)
- Profit/loss in $
Plus optional but valuable:
- Pre-bet fair-line estimate (your projected line vs the market's posted line)
- Confidence rating (1-5 — how high-conviction is this?)
- Bet thesis (one-line description of why)
- Key info / news source (what made this bet attractive)
The right tool
Three tiers, depending on volume and seriousness:
- Spreadsheet (Google Sheets / Excel). Free. Sufficient for <500 bets/year. Manual entry. Easy to add custom analysis. Recommended starting point.
- Bet-tracking apps (Pikkit, BettingTracker.io). Auto-import from major US sportsbooks. ~$10-15/month. Worth it once you cross 500-1,000 bets/year and want cross-book aggregation.
- Custom database / scripted ingestion. For high-volume bettors who need real-time CLV calculation, conditional alerts, and integration with model outputs. Build only if your volume justifies it.
The base spreadsheet schema
| Column | Type | Why |
|---|---|---|
| Date | Date | Time-series analysis |
| Sport | Text | Performance by sport |
| Market | Text | Performance by market type |
| Selection | Text | Reference |
| Odds (American) | Number | Stake-and-payout math |
| Stake | Number | P&L |
| Book | Text | Performance by book |
| Close | Number | CLV calculation |
| Result | Text | W/L/Push/Void |
| P&L | Number (formula) | Cumulative tracking |
| CLV % | Number (formula) | Forward-looking edge |
The analyses that matter
Once you have 200+ bets logged, run these analyses monthly:
- Overall ROI and CLV. What's your bottom line? What does CLV say about whether your process is sound?
- By sport. Are you a 55% NFL bettor and a 47% MLB bettor? Maybe stop betting MLB.
- By market type. Profitable on game lines, losing on parlays? Common pattern. Adjust accordingly.
- By book. Some books give you better closing-line edge than others. Concentrate volume there.
- By stake size. Are your high-confidence bets actually outperforming your normal bets? Or is variance fooling you?
- Day of week / time of day. Some bettors lose disproportionately on Sunday-night impulse bets. Pattern recognition.
The CLV computation
CLV (closing line value) = (your_odds_implied_prob - closing_odds_implied_prob) / closing_odds_implied_prob × 100. Positive CLV means you got a better number than the market closed at — i.e., you're beating the market's most-informed estimate. Sustained positive CLV (1.5%+ on a 200+ sample) is the strongest indicator of edge. CLV deep dive.
What tracking changes about how you bet
The discipline of recording every bet — including the embarrassing ones — sharpens decision-making in subtle ways. You start asking 'will I actually want to log this bet?' before placing. Impulse bets feel less attractive when you know they'll appear in the log. Pre-bet fair-line estimates force you to commit to a number before seeing the market.
Most bettors who start tracking find that 60-70% of their volume comes from a small set of repeated bet types. The other 30-40% is noise — bets they wouldn't have placed if they'd thought about it. Eliminating that noise alone is often worth 1-2% of EV.
Discipline rules
- Log immediately. Don't batch up bets at end of day; entries get sloppy.
- Track CLV alongside W/L. Without it, you're flying blind.
- Review weekly. Quick spot-check on patterns, drawdowns, deviations.
- Review monthly with depth. Run the analyses above. Adjust strategy.
- Don't game your own log. The point is honesty with yourself.