Conversation so far:
What were the Baseball Abstracts?
Featuring 18 categories of statistical information that you just can't find anywhere else, presented 68 pages of in-depth statistics compiled from James's study.
When was it printed?
The Bill James Baseball Abstract beginning in 1977.
What were some of the categories in it?
James's study of box scores from the preceding season and was offered for sale through a small advertisement in The Sporting News.

Question: how many copies have been sold?
Self-contained rewrite: How many copies of the Bill James Baseball Abstracts have been sold?