When creating a presentation, it's important to remember that you need to think about whether your audience is a beginner, intermediate, or advanced in their knowledge of the topic. You may need to create different presentations for different audiences. It will be beneficial to have at least a couple of different versions of the presentation: a detailed one and a less detailed one. You may even need to create different presentations for different formats or purposes, such as for a website or compliance reasons. 

For baseball data storytelling, your audience will most likely be people who are familiar with and interested in baseball. Still, it can't hurt to include some information about the basics if you want to add people who don't know as much about baseball. It can be essential to show your presentation to someone who doesn't know the topic matter well to see if they understand what you are trying to explain.