MLB Data Dictionary

Each MLB season — spring training, the 162-game regular season, the Wild Card Series, the Division Series, the League Championship Series, and the World Series.

The 30 MLB franchises, organized into the American and National Leagues with three divisions in each.

Every scheduled and played MLB game — spring training exhibitions, the 162-game regular season, the Wild Card Series, the Division and Championship Series, and the World Series.

Every individual who has played in Major League Baseball — current 26-man and 40-man rosters, minor-league call-ups, players on the injured list, free agents, and retired players.

Each half-inning of every MLB game — runs scored, hits, errors, base traffic, plate appearances, who pitched, and how the offense ended each frame.

Every individual pitch thrown in every MLB game — the pitch type, velocity, location, movement, spin, and the result (called strike, swinging strike, foul, ball, hit, walk).

Every plate appearance in every MLB game — the batter, the pitcher, the count, the pitch sequence, and the outcome (single, double, home run, strikeout, walk, hit-by-pitch, etc.).

Every individual play of every MLB game — every plate appearance, baserunning event, defensive play, and substitution with the inning, outs, base state, and score at the moment.

How each MLB ballpark inflates or suppresses run-scoring categories — runs, home runs, doubles, triples, and batting average relative to a neutral park, computed per season.

League-wide offensive context per MLB season — average runs per game, league batting line, ERA, and the offensive baseline used to normalize player and team stats across eras.

The weighted on-base average coefficients for each MLB season — the run values assigned to walks, singles, doubles, triples, and home runs, used to compute wOBA and wRC+.

How each sportsbook and fantasy operator names every MLB team — the mapping from each operator's team code to the unified franchise record.

Season totals for each MLB team — wins and losses, runs scored and allowed, batting and pitching aggregates, fielding stats, and advanced team metrics (BaseRuns, pythagorean expectation, run differential).

Each batter's box-score stat line for each MLB game — at-bats, hits, doubles, triples, home runs, RBIs, walks, strikeouts, stolen bases, and runs scored.

Each pitcher's box-score stat line for each MLB game — innings pitched, hits and runs allowed, earned runs, walks, strikeouts, home runs allowed, and pitches thrown.

Each MLB team's stat line for each game — runs, hits, errors, batting averages, pitching lines, broken out per game with home/away context.

How each sportsbook and fantasy operator names every MLB player — the mapping from each operator's player identifier to a unified player record.

Season totals for each MLB player — the full batting line (AVG, OBP, SLG, OPS), counting stats (HR, RBI, SB, R), and pitching line (W, L, ERA, WHIP, K, BB). Advanced run-value metrics (wRC+, FIP, WAR) are not carried here. Scope is not split by season type.

Series-level odds for postseason MLB matchups — who wins each series and how many games it goes, with the price updating game by game as the series unfolds. MLB playoff series are best-of-5 (LDS/WC) or best-of-7 (LCS/WS).

Alternate MLB game lines — the full ladder of run-line and total offerings at non-standard prices that sportsbooks publish alongside the headline line.

MLB game betting lines — moneylines, run lines (the baseball point-spread equivalent), and over/under totals from sportsbooks, captured over time as the lines move from opening to closing. In MLB, spread = run line (typically +/- 1.5).

Period-specific MLB betting lines — first-five-innings markets (F5), individual-inning bets, and other partial-game spreads, moneylines, and totals. Each row is a time-series snapshot - only captured when values change.

MLB player prop bets for each game — hits, runs, RBIs, total bases, home runs, strikeouts (for pitchers), and other player-statistic markets offered by sportsbooks.

The active gameday roster for each MLB team in each game — the 26 players in uniform that day, with positions and any pre-game lineup designations.

Day-by-day player-to-team affiliations across the MLB season — who was on each 40-man roster, who was on the IL, who was optioned to the minors, and who was designated for assignment.

Each batter in each MLB starting lineup — position in the order (1 through 9), defensive position, and batting handedness for the day.

Each MLB team's starting lineup for each game — the nine batters in batting order plus the starting pitcher (and DH where applicable).

MLB ballparks — current home stadiums and historical venues, with dimensions, surface, capacity, and roof type.

MLB umpires — the four-person crew of home-plate, first-base, second-base, and third-base umpires who work each game (six in the postseason with outfield umpires added).

Outfield dimensions and wall heights for each MLB ballpark — distances to left field, center field, right field, and the power alleys, plus the height of the outfield walls.

Networks, regional sports networks, and streaming services that air MLB games — Apple TV+, ESPN, FOX, TBS, MLB Network, MLB.TV, plus team-local RSNs.

The MLB postseason bracket — Wild Card Series, Division Series, League Championship Series, and the World Series, tracked as the seeded matchups and outcomes.

Which networks broadcast each MLB game — the national TV partner, regional carriers, radio calls, and streaming providers.

The umpiring crew assigned to each MLB game — who worked home plate, who worked each base.

MLB player awards — MVP, Cy Young, Rookie of the Year, Gold Gloves, Silver Sluggers, All-Star selections, and other end-of-season honors.

The ongoing injury record for each MLB player — body part, severity, IL designation (10-day, 15-day, 60-day), and expected return timeline.

News about MLB players — trades, IL placements, lineup decisions, suspensions, and general beat-reporter updates, unified from beat-writer scrapers, operator feeds, and AI summarization.

On-field weather throughout each MLB game — temperature, wind direction and speed, humidity, and precipitation captured at fixed intervals from first pitch.