Martin Manley has created the first player evaluation metric which has been incorporated by NBA.com. In the late 1980s, he wrote “Basketball Heaven” books in which he outlined his production ratings, statistical indexes which measure the overall production of players and teams. In the book, he discusses his formula and variations, and compiles indexes for all players in the NBA.
In his efficiency formula, all stat categories are weighted the same. Also, these ratings are not adjusted for game pace. Thus they do not have the precision of possession based stats