Our baseball data comes from a variety of sources, contributors and collaborators over the years. For those users looking to work with large amounts of data, there are a few free sources that might be useful for users with some programming and/or database experience:
There is a ton of data available to search and filter with on Stathead.com/baseball. For a complete list of what we do and do not have on the site, including which stats are available for which time periods and when they are missing, please see our comprehensive Data Coverage page on Baseball-Reference.com. On that page you'll find complete information on our full season stats, play-by-play, weather data, pitch data, hit location and batted ball type data.