MLB Prop Bet Record Keeping: How to Track, Analyse and Improve Your Results
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You Cannot Improve What You Do Not Measure
For my first 18 months of prop betting, I tracked nothing. I had a vague sense of whether I was up or down, a rough memory of my biggest wins and a convenient amnesia about my worst losses. Then I started a spreadsheet, and within two months I discovered that my strikeout prop win rate was 57% while my total bases win rate was 44%. I had been subsidising a losing market with the profits from a winning one — and I had no idea until the numbers showed me.
Only 3-5% of sports bettors are profitable over the long term, and a defining characteristic of the profitable minority is meticulous record keeping. Not because the act of recording bets magically improves results, but because the data reveals patterns — strengths, weaknesses, biases and leaks — that are invisible without it. Your memory lies. Your spreadsheet does not.
What to Record for Every MLB Prop Bet
The minimum viable tracking sheet contains seven fields. Anything fewer, and you lose the ability to segment your data meaningfully. Anything more, and the maintenance burden becomes a reason to stop tracking.
Date and game: when the bet was placed and which game it covered. This allows you to filter by time period and by team/opponent.
Prop type: strikeout over, total bases under, home run yes, walks over, and so on. This is the single most important field for analysis because it lets you compare your performance across different markets.
Line and odds: the number on the line (e.g., 5.5 strikeouts) and the decimal odds at which you placed the bet (e.g., 1.87). Without the exact odds, you cannot calculate ROI or closing line value.
Stake: the amount wagered in pounds. This is essential for calculating return on investment and for verifying that your staking plan is being followed consistently.
Result: win, loss or push. Self-explanatory but easily neglected when losses accumulate.
Closing odds: the odds on the same market approximately 30 minutes before game time. This allows you to calculate closing line value, which is the most reliable measure of whether your process is identifying genuine value.
Notes: a free-text field for any contextual information that might be useful during a future review. Was the lineup changed late? Did the weather shift? Was the bullpen depleted? These notes become invaluable when you review your results and try to explain why certain bets won or lost.
Calculating ROI and Yield Across Market Types
Two metrics tell you whether you are profitable: ROI and yield. They measure slightly different things, and both are necessary.
ROI (return on investment) is calculated as: (total profit or loss) / (total amount staked) x 100. If you have staked 2,000 pounds over two months and your balance has grown by 80 pounds, your ROI is 4%. A positive ROI means you are profitable. A negative ROI means you are not. Simple, but the aggregate number hides as much as it reveals.
The power of ROI comes from segmentation. Calculate ROI separately for each prop type: strikeout overs, strikeout unders, total bases overs, home run yes, walks overs, and so on. The segmented view will almost certainly show that your performance varies significantly across market types. You might carry a 6% ROI on strikeout overs and a -4% ROI on total bases overs. Without segmentation, the aggregate number is 1% — marginally profitable but unremarkable. With segmentation, the path forward is obvious: increase volume on strikeout overs and reduce or eliminate total bases overs until the process improves.
Yield is ROI expressed per bet rather than per pound staked. If your ROI is 4% across 150 bets, your yield per bet is 4%. Yield is useful for comparing your performance to benchmarks. A yield of 3-5% is strong for a prop bettor. Above 5% is exceptional and may indicate either genuine skill or a sample too small to be statistically meaningful. Below 0% over 300+ bets is a clear signal that the process needs revision.
The minimum sample for meaningful ROI analysis is 200 bets. Below that number, variance dominates the result and the ROI figure is unreliable. A bettor who is 10% up after 50 bets may be skilled or lucky — the data cannot tell you which. After 200 bets, the signal begins to emerge from the noise. After 500 bets, you have a reasonably reliable picture of your true skill level by market type.
Reviewing Records for Patterns and Leaks
Data collection without analysis is a filing exercise. The value of your tracking sheet is in the patterns it reveals when you sit down to review it — and I recommend doing that review once per month.
Start with the segmented ROI by prop type. Identify your strongest and weakest markets. Then ask why. Is the strong market strong because you have a genuine analytical edge — better data sources, a more refined model, deeper domain knowledge — or because the sample is small and you happened to hit a lucky stretch? Is the weak market weak because you are systematically overvaluing a variable, or because you have been chasing a narrative that the data does not support?
Next, check for time-of-day patterns. Do you perform better on bets placed in the morning, when you have time for full research, or on bets placed hastily in the evening before game time? Many bettors find that their late-add, impulse bets carry significantly lower win rates than their planned, pre-researched bets. If the data confirms that pattern, the fix is behavioural: stop placing impulse bets.
Look at your closing line value trend. Is it positive or negative, and is it stable, improving or deteriorating? A declining CLV trend over three months suggests that either the market is becoming more efficient at pricing the edges you were exploiting, or your process is drifting from the discipline that produced the initial edge. Either way, it is a signal to reassess.
Finally, check the staking discipline. Did you follow your unit-sizing plan, or did you deviate — placing larger bets on “sure things” or smaller bets when confidence was low? If deviations occurred, compare the results of plan-adherent bets to deviated bets. The data almost always shows that deviation hurts. Confidence-based sizing is only effective if your confidence calibration is accurate, and most bettors discover through their records that their subjective confidence is poorly correlated with actual outcomes.
Record keeping is the least exciting part of MLB prop betting. It does not produce thrilling wins or social-media highlights. What it produces is knowledge — about yourself, your strengths, your weaknesses and your genuine edge. That knowledge is the raw material from which a sustainable, profitable prop-betting operation is built.
What is the minimum number of tracked bets before ROI becomes meaningful for MLB props?
A minimum of 200 bets is needed before ROI figures begin to reflect genuine skill rather than short-term variance. Below that threshold, a positive or negative ROI is equally likely to be driven by luck. After 500 bets, the data provides a reasonably reliable picture of your true performance by market type. Segmenting ROI by prop type — strikeout overs, total bases unders, home run props — accelerates the learning process by revealing which markets produce your genuine edge.
Which free tools or templates work best for tracking MLB prop bets?
A basic spreadsheet application — whether a desktop programme or a free cloud-based tool — is sufficient for tracking MLB prop bets. The essential columns are date, game, prop type, line, odds, stake, result, closing odds and notes. No specialised software is required. The value comes from consistent data entry and monthly review rather than from the sophistication of the tool itself.
Written by the editors at mlb bet Props.
