Bill James' Baseball Abstract books published in the 1980s are widely considered to be the modern predecessor to websites using sabermetrics such as baseballthinkfactory and baseballprospectus.
The site's emphasis on sabermetric baseball analysis attracted members of the rec.sport.baseball Usenet groups, and later drew readers of Rob Neyer's ESPN columns.
The early site cultivated spirited discussions as a result of the Usenet veterans' familiarity with each other and the fact that registration was not required to post comments.
These include: BTF has featured numerous original research articles, primarily under the aforementioned sub-sites "Transaction Oracle," "Dialed In," and "Primate Studies."
Several analysts such as Mitchel Lichtman and Tom Tango regularly posted original research articles and participated on discussion and criticism of the work at BTF before going on to establish their own sites and to publish results in book form.
Litchman combines this play-by-play data with his linear-weights system that assigns run values to the various baseball plays and their context within the game (inning, runners on base, score, etc.)