My comparison of the two is here; http://thatwasnotinthebook.com/diff/rollerball-murder-vs-rollerball
Thats an interesting site. As a kid in the 80s I almost always read the book of all the big films first . Not sure why it panned out out like that . I had little access to films i guess.
Worth mentioning that the "book", in this case, is a short story.