Some internet research indicates that before the 80s, NBA player heights were listed as height without shoes. Then it changed to height with shoes without any central plan to change a 'regulation,' or anything like that. Further research indicates that there is significant variation to be expected in players' measurements depending on a range of variables. DX became something of a standard (but it isn't clear how they were gathering all their listed heights; and now that Givony is gone, will they be retained as a standard?); before that measurements were collated from several independent sources (i.e. motives unclear). Errors are expected if they are converted from metric system. Etc. Also, many of the youngest players grow after the measurement that was last published, and no efforts are made to update them (KD is the famous example). ...Hardly the work of a 'standard' -- unless your definition of standard is loose, sloppy AF, and generally unconcerned with facts.