Most bettors think their memory is enough to track performance—until a downswing hits and feelings rewrite the past. A simple ledger cuts through bias by turning every wager into clean data: stake, odds, result, and context. With a few consistent fields, you can see which markets you beat, where you leak EV, and how variance—not bad judgment—explains some losing streaks. The point isn’t perfection; it’s decision support. A lightweight system that takes seconds per bet will get used, and used consistently. Over a month, patterns emerge: you might crush player props but donate on parlays, or beat the close on sides yet lose to juice due to staking. A ledger gives you a calm, objective voice when emotions run hot, and it’s the quickest path to better unit sizing, sharper market selection, and tighter discipline.
What to Record (The Minimum That Matters)
Capture the few fields that drive insight without slowing you down. For each bet, note: date and sport, market type (spread, total, prop), book used, odds at bet, stake, and result (win/loss/push and payout). Add two high-value context points: closing line (for CLV) and a brief thesis (“pace uptick with backup center”). Optional but useful: whether it was live or pre-game, unit size, and a confidence tag (low/med/high) you can audit later. Avoid essay-length notes; your future self needs quick scanning, not prose. Consistency beats detail—six fields logged every time will outperform twenty fields logged sporadically. Finally, separate parlays into legs in a second tab so you can evaluate selections and ticket construction independently.
A Simple Structure You’ll Actually Use
Start with one tab per sport or keep everything in one table and filter. Here’s a compact schema you can copy:
| Date | Sport | Market | Odds (Dec) | Stake | Book | CL (Dec) | CLV | Result | Net | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| 2025-09-12 | NBA | Total O/U | 1.91 | 1.0u | Book A | 1.83 | +0.08 | Win | +0.91u | Pace up; injury news |
| 2025-09-13 | NFL | Spread | 1.95 | 1.0u | Book B | 1.91 | +0.04 | Loss | −1.00u | Weather misread |
CLV (closing line value) is Odds_at_bet − Closing_odds in decimal; you can also store the percentage edge. Keep formulas simple: Net = (win odds − 1) × stake for wins, −stake for losses, 0 for pushes. Color code by CLV (green positive, red negative) so value trends pop even when outcomes don’t. Automate drop-downs for sport/market to prevent typos and keep filters clean. If you hate spreadsheets, a notes app with a structured template per bet works—just don’t sacrifice fields you need for analysis.
Turn Data into Decisions (Weekly Review Checklist)
A ledger earns its keep during review, not entry. Once a week, run a 15-minute audit:
- Hit rates by market: sides vs totals vs props—where are you actually winning?
- Average CLV: are you beating the close overall and by sport? If not, your timing or sources need work.
- Unit distribution: are “high confidence” bets outperforming standard plays, or should they be sized the same?
- Bad beats vs bad bets: re-read notes—was the loss variance or thesis failure?
- Parlay leakage: did legs have value, or did correlation traps eat EV?
Convert insights into small rule changes: ban one low-performing market for two weeks, lower units on live bets until CLV improves, or commit to line shopping before placing any total. Iterate lightly; big swings in rules create new noise.
Guardrails That Keep the Ledger Honest
A tracker is useless if tilt bypasses it. Add process guardrails: log before confirming the bet (forces a pause), and don’t place a second wager until the first entry is saved. Cap daily entries—if you’re spraying, you’re not selecting. Separate wallets by vertical (sports/tables/slots) so you don’t “borrow” to chase. At month-end, produce one page: ROI by market, average CLV, max drawdown, and action items for the next month. If CLV is consistently negative, prioritize speed (news, alerts, earlier limits) or specialize in slower, niche markets. If CLV is positive but ROI lags, reassess staking—fractional Kelly or stricter flat units can narrow variance. The ledger doesn’t have to be fancy; it just has to be faithfully maintained. With that habit, your bets stop being anecdotes and start being a strategy.