The PDGA social media / event guy is here. Can't remember his name? The dual 18 layout has been in use for over a decade. It was first used for a local non-sanctioned event called HabRec that has been running every year since either 2001 or 2002. I played the layout in the 2004 BSF, but I am not sure when the "HabRec" tournament layout was first incorporated into the BSF. As Matt said, there have been numerous small changes along the way to improve the course's performance, however the all the fairways have effectively been the same for a very long time.