Most sports bettors track their results in a spreadsheet — they know their profit and loss, but they miss the metrics that matter most for evaluating whether their results are sustainable.
Our Portfolio Bet Tracker goes beyond simple P&L. Paste your betting history in bulk and the tool calculates ROI, Closing Line Value (CLV), a statistical significance test (T-Score / P-Value), and a 95% Confidence Interval for your true long-run yield. These metrics help separate signal from noise — whether your profits reflect a genuine edge or fall within the range of normal variance.
🔒 Privacy: This tool runs entirely in your browser. Your data is never sent to any server. Refresh the page and it is gone.
Portfolio Bet Tracker
BATCH ANALYZER100, 2.0, W, 1.95 | Result: W / L / P / HW / HL | Closing Odds optional (needed for CLV). Avg CLV = mean of all CLV values where closing odds were provided
Std Dev = sqrt( sum((yield_i - mean)^2) / n )
Std Error = Std Dev / sqrt(n)
T-Score = Mean Yield / Std Error
Uses normal CDF approximation (Abramowitz & Stegun).
- Bets treated as independent events (no correlation between outcomes).
- All odds in decimal format.
- Closing odds optional — CLV only calculated for bets with closing odds.
- Variable stake sizes: t-test uses per-bet yield (profit/stake) with equal weighting. For portfolios with highly unequal stakes, results are approximate.
- Small samples (<30 bets) produce unreliable statistics. 200+ bets recommended; 500+ for meaningful confidence.
- CLV is a leading indicator, not a guarantee. It measures whether you consistently got better prices than the closing market.
How to Use the Portfolio Bet Tracker
This tool is designed for batch processing — you do not need to enter bets one by one. Copy data from Excel, Google Sheets, or a text file and paste it directly.
1. Prepare Your Data
Each line represents one bet in CSV or tab-separated format:
Stake, Odds, Result, [Closing Odds]
- Stake: Bet amount (e.g., 100).
- Odds: Decimal odds you took (e.g., 1.95).
- Result: W (Win), L (Loss), P (Push), HW (Half-Win), HL (Half-Loss).
- Closing Odds (optional): The decimal odds when the market closed. Required for CLV analysis.
The tool accepts both commas and tabs as separators, so you can paste directly from Excel without reformatting.
2. Paste and Analyze
Click “Analyze Portfolio” to generate the dashboard. The tool shows how many bets were parsed and how many lines were skipped (invalid format).
The Formulas
ROI (Yield): Total Profit / Total Staked. Measures historical return per dollar wagered.
CLV Edge (per bet): (Your Odds / Closing Odds) − 1. Measures whether you consistently got better prices than the market’s final assessment. Average CLV = mean across all bets where closing odds were provided.
T-Score: Mean Yield / Standard Error, where Standard Error = Std Dev / √n. Tests whether the observed ROI is statistically different from zero.
P-Value: One-tailed probability that the observed positive ROI is due to chance. A lower p-value means stronger evidence of genuine edge. Under 5% is conventionally called “statistically significant,” but this is a model-dependent diagnostic, not a definitive proof.
95% Confidence Interval: Mean Yield ± 1.96 × Standard Error. The estimated range where the long-run ROI is likely to fall, given the data and the model’s assumptions.
Understanding Your Metrics
ROI vs. CLV: Lagging vs. Leading Indicator
ROI tells you what happened — it is a backward-looking measure of realized profit. CLV tells you about the quality of your line shopping and timing — it is a forward-looking indicator.
The relationship between them is the most informative diagnostic:
- Positive ROI + Positive CLV: The strongest signal. Both your results and your market-beating indicate an edge.
- Positive ROI + Negative CLV: Results are good, but you are consistently getting worse prices than the closing market. This pattern is unlikely to be sustainable — the ROI may be driven by variance.
- Negative ROI + Positive CLV: You are beating the line but losing money. This is consistent with bad variance on a sound approach. On a longer sample, positive CLV tends to translate into positive ROI.
- Negative ROI + Negative CLV: No evidence of edge. Both metrics point the same direction.
The Confidence Interval
The 95% CI gives a range: for example, if your ROI is 5% with a CI of −2% to +12%, this means the data is consistent with a long-run ROI anywhere in that range. As your sample grows, the interval narrows. With fewer than ~200 bets, the interval is usually too wide to draw conclusions.
P-Value
A p-value under 5% is conventionally interpreted as “the result is unlikely to be explained by chance alone.” But this depends on assumptions (independent bets, stable strategy, representative sample). It is a useful diagnostic, not a certification of skill.
How Many Bets Do You Need?
Sports betting has enormous variance. Rules of thumb:
- <30 bets: Too small for any meaningful statistical analysis.
- 30–200 bets: Directional signals only. Confidence intervals are wide.
- 200–500 bets: Patterns start to emerge. CLV becomes a useful filter.
- 500+ bets: Statistical tests begin to have real discriminating power. This is the minimum for serious self-assessment.
Limitations
- Bets treated as independent. In reality, correlated bets (same event, same day, parlays) violate this assumption and can inflate the t-score.
- Equal weighting per bet. The t-test treats each bet’s yield equally regardless of stake size. For portfolios with highly variable stakes, the results are approximate.
- No segmentation. The tool analyzes the portfolio as a whole. It does not break down by sport, market, bookmaker, or time period. A profitable niche can be hidden by an unprofitable one (and vice versa).
- CLV depends on closing odds quality. If the closing odds you enter are from a soft bookmaker rather than a sharp market (e.g., Pinnacle), the CLV metric is less meaningful.
- Model-dependent diagnostics. The p-value and confidence interval assume a specific statistical model. They are useful indicators, not definitive verdicts.
Related Tools: To size your bets based on edge, see the Unit & Stake Calculator. For single-bet EV analysis, try the No-Vig Calculator.
Frequently Asked Questions (FAQ)
Can I paste from Excel?
Yes. Highlight your columns (Stake, Odds, Result, Closing Odds), copy, and paste directly. The tool reads both comma-separated and tab-separated data.
What does Closing Line Value (CLV) mean?
CLV measures whether you got better odds than the closing market price. If you bet at 2.10 and the line closed at 1.95, your CLV = (2.10 / 1.95) − 1 = +7.7%. Consistently positive CLV is the strongest available indicator that a bettor has an edge, because it means you are systematically finding mispriced lines.
Why does the assessment say “Sample too small”?
Variance in sports betting is extreme. With fewer than 30 bets, any statistical test is unreliable — the confidence interval is too wide to distinguish skill from noise. The tool needs at least 200+ bets for directional signals and 500+ for robust conclusions.
Is my data private?
Yes. The entire analysis runs in your browser using JavaScript. No data is transmitted to any server. When you close or refresh the page, the data is gone.
Why is positive CLV with negative ROI a good sign?
Because CLV measures process quality (line selection) while ROI measures outcome (wins and losses). Outcomes are subject to variance — you can make correct bets and still lose over short samples. Positive CLV means the market agreed you had an edge at the time of the bet. Over larger samples, CLV and ROI tend to converge.