Ask HN: Source code for sports games

This is a really niche question, but does anyone know of source code available to review for sports games? They can be really old sports games, like Star League Baseball or TV Sports Football. Or more modern games.

It's an area of coding that has always interested me, but I've never done it myself. I'd love to see some code that I could read for this genre. Biggest areas of interest are the AI, general code structure, animation, the way sports rules are handled, etc...