Baseball's Big Bois

This R script pulls physical data (height and weight) for active baseball players across all levels of an MLB organization's system, from the major league club down to the Rookie/DSL levels. It queries the public (but undocumented) MLB Stats API and exports a clean, unified CSV dataset. There isn't really a good existing way to pull this information systematically.

Features

• Full Organizational Depth: Pulls data for MLB, AAA, AA, High-A, Single-A, Rookie, and DSL/ACL affiliations.
• Data Cleaning: Automatically converts raw string heights (e.g., "6' 2\"") into a clean height_in integer column (e.g., 74).
• Org Mapping: Maps minor league players to their parent MLB organization for easy grouping and analysis.

Prerequisites

This script requires R and the following packages:

• httr - For making API requests.
• jsonlite - For parsing the JSON responses.
• dplyr - For data manipulation.
• purrr - For mapping over the different sport/level IDs.
• readr - For writing the final CSV.

You can install any missing packages using:

install.packages(c("httr", "jsonlite", "dplyr", "purrr", "readr"))

How to use

Clone this repository to your local machine.

Open the R script (e.g., baseball_bigbois.R) in RStudio or your preferred environment.

Run the script.

The script will fetch the data level by level, printing progress messages to the console.

Output

The script generates a CSV file named mlb_milb_players_2026.csv in your working directory.

Data Dictionary:

Column	Type	Description
player_id	Integer	The MLB Stats API unique identifier for the player.
full_name	String	The player's first and last name.
position	String	The player's primary position abbreviation (e.g., "P", "SS").
height_in	Integer	The player's height in total inches.
weight	Integer	The player's weight in pounds.
team	String	The specific team the player is currently assigned to (e.g., "Norfolk Tides").
organization	String	The parent MLB organization (e.g., "Baltimore Orioles").

Notes on the MLB Stats API

This script relies on the MLB Stats API (statsapi.mlb.com/api/v1). Because this API is largely undocumented and subject to change by MLB Advanced Media, endpoints or data structures could shift over time. Currently, the script is configured to pull rosters for the 2026 season.