Blog · September 9, 2026 · 3 min read
Sports betting bankroll tracker: what to log, and the 4 numbers that show if you have an edge
Units, yield, ROI, closing line value and drawdown — what a betting tracker should log per bet, with a free CSV template and the formulas for each number.
A bankroll tracker is not a list of wins and losses. It is the only tool that can tell you, over 500 bets, whether you are good or lucky — and which markets, days and stake sizes carry the edge. Here is what to log per bet and the four numbers to compute from it. Template: sharpen-betting-template.csv.
Log this for every bet
| Column | Example | Why |
|---|---|---|
| Date placed | 2026-09-07 18:40 | Time of day and weekday effects are real |
| Event | Chiefs vs Ravens | Sport and league come from here |
| Selection | Ravens +3.5 | Market type: spread, moneyline, total, prop |
| Stake | 50 (or 1u) | In units of a fixed bankroll fraction |
| Odds | 1.91 / −110 | Decimal or American; keep one format |
| Closing odds | 1.87 | The line at kickoff — needed for CLV |
| Result | won / lost / push | Settle every bet the same day |
| PnL | +45.50 | Net of the stake, net of any fee |
| Planned | yes / no | Was it in your list before the day started? |
| Emotion | 1–5 | 5 = chasing. Logged at placing time |
Stake in units (1u = 1% of the bankroll is the usual convention) is what lets you compare a $20 month to a $200 month.
The four numbers
1. Yield = net profit ÷ total staked. The betting equivalent of expectancy per unit risked. Over a large sample, 3–5% is a genuine edge against sharp books; double digits over a few dozen bets is variance, not skill.
2. ROI on bankroll = net profit ÷ starting bankroll for the period. This is what you actually made, and it depends on stake sizing as much as on picks.
3. Closing line value (CLV) = how often (and by how much) your odds beat the closing odds. If you consistently get 1.91 on a line that closes at 1.85, you are beating the market even in a losing week — CLV is the earliest honest signal of an edge, long before yield stabilizes.
4. Max drawdown = the largest peak-to-trough drop of the bankroll, in units. It sets your stake size: if your history shows a 25u drawdown, 1u stakes on a 30u bankroll will bust you.
Worked example: 214 bets at 2u average, 428u staked, +16u net → yield 3.7%; starting bankroll 100u → ROI 16% for the period; CLV positive on 61% of bets; max drawdown 22u. That is a real edge — and a 22u drawdown on a 100u bankroll says the stakes are about as large as they should ever be.
Where the leaks hide
Split the log the way you would a trade log — see how to calculate expectancy and profit factor:
- Planned vs unplanned bets. Live bets and late adds after a loss are usually the entire leak.
- After two losses. Same tilt mechanism as in trading; the 90-minute rule applies.
- By market. Most bettors have one market (often player props or parlays) with a negative yield that drags the rest.
- By stake size. If your 3u bets have a lower yield than your 1u bets, your confidence is not information.
Spreadsheet or app
The spreadsheet holds the log fine. The comparisons above are what nobody rebuilds every week, and that is what Sharpen does on each CSV import: yield, ROI, drawdown, streaks, results by market and by day, plus the leak detectors (chasing after losses, oversized stakes, unplanned bets) with their cost in units. Free for 30 bets a month, $19/mo for unlimited.