Though a cohesive understanding of the game play of baseball might not be critical for the study of baseball, it certainly enhances your understanding of the history of the game. Being able to recognize different styles of play, both in terms of the rules themselves or trends among the players, helps to flesh out your understanding of the facts and fashions of baseball history.
National Baseball Hall of Fame. Retrieved April 23, 2020. https://baseballhall.org/
A resource that may seems questionable at first glance, the baseball hall of fame is a great way to familiarize yourself with the highpoints of the game and some of the players good (and popular) enough for recognition. The site also houses links to the Hall of Fame Museum and Archive, which offers digital browsing of part of the collection. This is a great way to flesh out a research paper, or even just what you know about a person or team.
Baseball Almanac: The History of Major League Baseball. Retrieved April 23, 2020. https://www.baseball-almanac.com/
Another web source, the Baseball Almanac has all of the benefits of a glossary but with a name/history leaning and a significantly larger bank. A great resource for revisiting a particular facet of the game, or wanting more information on a name that seems important.
Baseball Reference. Retrieved April 23, 2020. https://www.baseball-reference.com/
What would baseball be without its statistics? An interesting skim for those less interested in the numerical side of the sport, but worthy of a deep dive for the statistically-inclined. Navigating can seem a little intimidating at first (let me know if I can help!) but it is fairly intuitive and does have that handy search bar.
Baseball for Beginners. PBS. Retrieved April 23, 2020. https://www.pbs.org/kenburns/baseball/beginners/
Your understanding of history and players will likely benefit from a quick introduction to the mechanics of baseball. The link above offers a blurb of an introduction alongside an explanation of the statistics and a compiled glossary of some popular terms. Feel free to check out the video below for an introduction to the gameplay of baseball itself.
Ninh Ly. (2015, February 20). The Rules of Baseball - EXPLAINED! [Video]. YouTube. https://youtu.be/skOsApsF0jQ.
Hershburger, Richard. (2019). Strike Four: the evolution of baseball. Rowman & Littlefield Publishers.
As you can likely imagine, this is an analysis of baseball from the ground up. A great resource for the new researcher and the old hat alike, this resource really takes the time to break down different aspects of baseball and look at their origin and history. Good for those not super familiar with the technicalities, but also offers some analysis of baseball as an institution.
Dreifort, Richard. (2001). Baseball history from outside the lines : a reader. University of Nebraska Press.
A reader is a great way to get a glimpse at a multitude of eras and issues on a topic. This resource certainly lives up to the challenge. Some of the major topics in baseball, such as the color line, prominent players, the social meaning of baseball are introduced, as are authors and sources relevant to these topics. If you want to know a bit about a lot of topics, but would prefer it in short bursts, this may be the way to go.