The 1979 Statis Pro Baseball boxed set came with the first edition rules. They are a masterclass in simplicity and brevity, running in total for four pages. Only the first page and a half contain the actual rules, while the remaining pages provide detailed information on how to create player cards.

As far as I can tell there were three editions of the rules for the Avalon Hill version of Statis Pro Baseball, and the rules included in the 1979 book would be considered version one. The most complex came later in version two, which more detailed rules around pitcher management amongst other things. By the late 80s, early 90s simplicity was once again the hall mark and the 3rd Edition was reduced back to 4 pages.

Click on the link below for a high quality scan of the rule book.