MLB Fundamentals for Developers

This page provides a high-level overview of Major League Baseball concepts for developers who are new to baseball. It explains how MLB is structured and how real-world baseball mechanics map to data available in the Sportradar MLB API.

What Is MLB?

Major League Baseball (MLB) is a professional team sport in which 30 teams compete over a 162-game regular season, followed by a postseason tournament that culminates in the World Series.

Unlike clock-based sports, baseball is structured around innings, outs, and plate appearances rather than timed quarters or halves. Games progress through discrete events such as pitches, at-bats, and plays.

In the MLB API, seasons and games are accessed through the Seasons and Schedule feeds.

How MLB Is Structured

American League and National League

MLB consists of two leagues:

• American League (AL)
• National League (NL)

Each league is divided into three divisions (East, Central, West). League and division information is available in:

• League Hierarchy
• Standings

League structure is reflected in league.id, division.id, and team-level metadata within season and standings feeds.

Season Types

The MLB season includes multiple season types, identified using the required season_type parameter and returned as season.type in schedule and game feeds.

The following table lists the season types available in the MLB API.

During the Regular Season (REG), teams compete for division titles and Wild Card spots based on win percentage.

The Postseason (PST) via the series.title includes:

• Wild Card Series
• Division Series (ALDS / NLDS)
• League Championship Series (ALCS / NLCS)
• World Series

 <season-schedule id="e2c1d367-7f3d-4244-b8a9-8eefb1fcb062" year="2025" type="PST">
    <series title="ALDS - DET vs SEA" start_date="2025-10-04" id="f12b63ce-4ba8-4516-83c1-13a4754b816c" round="ALDS2" best_of="5" status="closed">
      <participant name="Tigers" record="2">
        <team name="Tigers" market="Detroit" abbr="DET" id="575c19b7-4052-41c2-9f0a-1c5813d02f99" seed="6"/>
      </participant>
      <participant name="Mariners" record="3">
        <team name="Mariners" market="Seattle" abbr="SEA" id="43a39081-52b4-4f93-ad29-da7f329ea960" seed="2"/>
      </participant>

Season phase and postseason series data can be discovered through:

• League Schedule
• Series Schedule (For bracket and progression workflows, see Tracking MLB Playoffs).

How a Baseball Game Works

A baseball game consists of nine innings, with each inning divided into:

• Top half: Away team bats
• Bottom half: Home team bats

Each half-inning continues until three outs are recorded.

Game state is tracked through:

• inning
• inning_half (top/bottom)
• outs
• balls
• strikes
• runners (base occupancy)

This information is available in:

• Game Summary
• Game Extended Summary
• Game Play-by-Play
• Game Boxscore
• Game Play Statistics

Pitches, At-Bats, and Plate Appearances

Each offensive sequence follows this hierarchy:

Game → Inning → Half → At-Bat → Pitch → Play Result

Key pitch-level attributes include:

{
  "pitch_type": "FF",
  "start_speed": 96.4,
  "zone": 5,
  "outcome": "strike_swinging"
}

At-bat results include:

• Single
• Double
• Triple
• Home run
• Walk
• Strikeout
• Fielding out

These are represented within events, pitch, and at_bat objects in:

• Play-by-Play

Applications building live pitch trackers, strike zone visualizations, or play logs should rely on Play-by-Play as the authoritative event feed.

Lineups, Positions, and the Designated Hitter

Each team starts nine players:

Starting lineups and batting order are available in:

• Game Summary

Look for:

• lineup
• batting_order
• position
• starter (boolean)

For real-time lineup changes such as substitutions and pitching changes, use:

• Play-by-Play

For a full integration walkthrough, see Tracking Lineups and Game Rosters.

Pitchers and Bullpens

The starting pitcher begins the game. Relief pitchers enter during substitutions.

Pitching data includes:

• innings_pitched
• earned_runs
• strikeouts
• walks
• pitch_count

Available via:

• Game Boxscore
• Season Statistics

Pitching changes are surfaced in Play-by-Play as substitution events.

Scoring and Statistics

A run scores when a baserunner legally advances around all four bases and reaches home plate.

Game-level scoring is tracked through:

• runs
• hits
• errors
• left_on_base

These appear in:

• Game Summary
• Game Boxscore

Common Offensive Statistics

Common Pitching Statistics

These are available via:

• Season Statistics
• Player Profile

Ballparks and Game Context

MLB games are played in team-specific stadiums with unique dimensions.

Venue data is available through:

• Venues

Venue attributes include:

• name
• city
• state
• surface
• capacity

Weather and attendance may also be included in game-level feeds.

Standings and Rankings

Teams are ranked by:

• Wins (wins)
• Losses (losses)
• Win Percentage (win_pct)
• Games Behind (games_back)

Available in:

• Standings

Wild Card standings and division splits are also represented within standings feeds.

For implementation guidance, see Retrieving MLB Standings.

IDs and Data Relationships

MLB data is connected using unique identifiers for:

• Season
• League
• Team
• Game
• Player
• Venue

A typical data flow:

Seasons → Schedule → Game Summary → Play-by-Play → Boxscore → Season Statistics

Understanding ID propagation is critical when linking game events to season-level statistics.

See ID Handling for best practices.

Mapping MLB Concepts to API Feeds

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More Questions?

Check our MLB API FAQ or contact support at [email protected]