If David Arneson was one of the father of the roleplaying game David Wesely is the grand father. His Braunstein games inspired Arneson to create Castle Blackmoor which led to all that followed.
Theory in the Closet interviews David Wesely and what a great interview it is. I really related to the description of the Braunstein game as it was roleplaying with a bit of live-action (milling around talking to people). His description of being up to 2am and talking to people at various times during the game mirrors my experience of being an event director of a NERO live-action event.