Heeren was probably the most famous NBA statistical analyst. Also a columnist for USA Today, Heeren wrote a series of books under the Basketball Abstract name. These were based on what is generally considered the first linear-weights player rating system, TENDEX. Heeren also wrote some columns for CBSSportsline.com a few years ago. Since then, Heeren has written about preps for the South Florida Sun-Sentinel and peddled his TENDEX ratings for teams looking to evaluate NCAA players.