How The Moneyball Lab Works
We're a small team running an MLB moneyline model. Each morning we publish today's slate with the bets our model thinks have an edge over the sportsbook line.
The Model
We use machine learning trained on pitching and hitting stats — pitch-level data, plate discipline, expected outcomes (xERA, xFIP, xwOBA), recent form. We layer in environmental factors that move runs around: ballpark, temperature, wind direction relative to the field. The output is a win probability for each side of every game.
The model is reviewed and refined every 100 bets — looking for tiers that are leaking money, situations where we're overconfident, edges that aren't holding up. What you see today is the current snapshot, not a frozen artifact.
The Tier System
Three baseballs in the top-left of every card tell you how much conviction we have:
Reading a Card
Each card on Today's Slate is a single MLB game with three columns of data on the right:
The picked team gets a green dot and the row is tinted. Below the model %, you'll see a small edge chip with the gap (e.g. +10.3%) — that's our advantage over the market.
All picks are theoretical straight bets — a single moneyline wager on one game's outcome, placed at the stated stake. No parlays, no in-game bets, no props, no exotic markets. The math is built specifically for single-game win probability vs. market price, and the track record assumes each pick is placed as its own standalone bet. Parlaying picks together breaks the model's assumptions and isn't reflected in any of the published ROI numbers.
Bets by Strength
In the header you'll see today's bet count by tier alongside lifetime win rate per tier. Useful for context: if our STRONG BETs are running 51% lifetime, that's profitable at the prices we get. Numbers update automatically as we close out bets and refine. CAUTION win rates are shown for visibility but the tier doesn't contribute to the overall ROI — see Tier System above.
Stake Sizing — Quarter Kelly
Each pick comes with a theoretical stake in dollars, sized via Quarter Kelly — one-quarter of the mathematically optimal stake for a given edge. Full Kelly is optimal in theory but the variance is brutal; the quarter version trades a small slice of theoretical edge for a much smoother bankroll ride.
All published stakes assume a reference bankroll of $1,000. If your bankroll is different, scale every stake proportionally — the ratio is what matters, not the absolute dollar amount.
Suppose the model publishes a $62 theoretical stake on a TOP PICK. Scaled to your bankroll:
- • For a balance of $500, the theoretical stake would be $31 (half)
- • For a balance of $1,000, the theoretical stake would be $62 (as published)
- • For a balance of $2,500, the theoretical stake would be $155 (2.5×)
Formula: your stake = published stake × (your bankroll ÷ $1,000)
The published Tracker ROI numbers are computed against the $1,000 reference bankroll. Your absolute P/L will be different, but the percentage return is the same as long as you scale proportionally on every pick.
Live State
When a game starts, cards update with live data automatically — no refresh needed:
Where the Data Comes From
We pull from reputable sources only — official MLB feeds, Baseball Savant, leading sportsbook odds, and weather services. No scraped tip sheets, no Twitter rumors, no recycled picks.
- Major League Baseball— Schedule, probable pitchers, live state, final scores
- Baseball Savant— Statcast metrics — expected outcomes, batted-ball data
- Leading sportsbook odds— Best-line aggregation across multiple books
- Weather services— Temperature and wind direction for every ballpark
Track Record
Every bet is logged with its outcome. Hit Tracker to see lifetime ROI, equity curve, and tier-level breakdowns. We don't hide losers.
Overall ROI is BET + STRONG BET only. bets are tracked at $0 stake — they show up in the tier breakdown so we can monitor their record, but they don't roll into the overall numbers.
The Calendar & Tracker
Past results live on two pages: the Calendar (P/L by day) and the Tracker (equity curve + tier breakdown). Both update automatically as bets settle.
The month view
Each month renders as a grid. Days with bets show net P/L and W-L; everything else is muted. You can move between months with the arrows and switch views with the toggle.
Reading a day cell
- Number top-left — day of the month.
- Pill top-right — how many bets ran that day.
- Big serif number — net P/L for the day (green for profit, rose for loss).
- Small line below — W-L record (with "p" suffix for any pending).
- Tinted background — subtle green/rose wash so you can scan the month at a glance.
- Accent ring — that day is today.
Click a day for the full breakdown
Tapping any day with bets opens a drawer listing every bet that ran, with its tier, opponent, odds, stake, and final outcome. It looks like this:
- LAD Dodgers vs SFSTRONG BET · TOP PICK · −145 · $62 stakeWon+$42.76
- NYY Yankees vs BOSSTRONG BET · −118 · $50 stakeWon+$42.37
- TBR Rays vs TORBET · +105 · $30 stakeLost−$30.00
Two views — All Bets vs Top Picks
- All Bets — every actionable BET and STRONG BET. The default. CAUTION is excluded.
- Top Picks — only the premium overlay tier (flask icon). A much smaller, higher-conviction subset.
- The ring around the month stats box changes color to match the active view — green for All Bets, purple for Top Picks.
- Whichever view you pick is reflected in your browser's address bar — so you can copy the link or bookmark it and come back to the same view later.
Tracker
The Tracker shows the same data rolled up differently: overall record, win rate, ROI, a per-tier breakdown, and a running equity curve. The equity curve has the same All Bets / Top Picks switcher — purple line when you're viewing the Top Picks overlay, green/rose when viewing All Bets by outcome.
Important — Read This
Not financial, investment, or betting advice. The information on this site is provided strictly for research and educational purposes.
Sports betting carries significant financial risk. Past performance does not guarantee future results. Our model is probabilistic by nature — outcomes are uncertain. We are not licensed financial advisors or registered tipsters.
Any decisions you make based on the information here are your own. We accept no liability for losses, damages, or other consequences arising from use of this site or its content.
Bet responsibly. Only wager what you can afford to lose. Sports betting is illegal in some jurisdictions — it's your responsibility to know your local laws. This site is not affiliated with Major League Baseball, any sportsbook, or any team.
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