Data provenance
TheCapper.io is built on official baseball data and sportsbook odds. This page tells you where every number on the site comes from, how often it refreshes, and where we still have gaps.
Schedules, lineups, probable starters, box scores, transactions, injury status, umpire assignments, and live game state come from the MLB Stats API. This is the same source the league publishes to its own apps. It's free and unlimited and there's no third-party middleman.
Pitch-level data — pitch type, velocity, exit velocity, launch angle, expected batting average, barrel rate, park factors, the full home-run tracker — comes from Baseball Savant, MLB's official Statcast platform. We use it to model pitcher arsenals against hitter tendencies and to translate batted balls across the 30 major-league parks.
The market lines and prices you see next to picks come from a paid odds feed that aggregates US sportsbooks. We capture the price the model saw at the moment a pick was made, plus the book that posted it. That captured price is what we grade picks against — not whatever line moves to later.
Per-stadium hourly forecasts (temperature, wind speed and direction, humidity) come from Open-Meteo, a free public weather service. We feed weather into the NRFI, strikeout, hit, and home-run models so wind blowing out of Wrigley or a cold night in Cleveland actually moves the projection.
During the slate, lineups, scores, and game state refresh every 30 minutes. Odds and projections refresh up to three times per slate — once in the morning, once after lineups settle, and once for next-day lines after games end. Pitch- level Statcast and rosters refresh overnight. Picks are graded the morning after each game and rolled into the public W-L record.
Every board, picks page, and tool surface displays a "last updated" chip so you can see exactly how fresh what you're looking at really is.