SABR

From Wiki Gonzalez

SABR = Society of American Baseball Research, a wonderful organization to which many Primates belong.

If you are interested in anything from statistics to history to the minor leagues to the business/labor aspects to scouting or any other aspects of the game, you should join.

Actually, if you like baseball and can afford the membership fee, you should join.

It even has its own website (http://www.sabr.org)!