FOR THE PAST 40 years, the San Francisco Comedy Competition has been a bellwether of rising comedic talent. Looking for proof? The first year, Robin Williams came in second. Other past participants have included the likes of Dana Carvey, Louis C.K., Ellen DeGeneres, Marc Maron, Patton Oswalt, Paula Poundstone, and Silicon Valley’s Jimmy O. Yang. This year there will be two preliminary rounds on consecutive Saturdays when the comics will have seven minutes for their chance at $15,000 in prize money and a shot at stardom. The competition takes place at the Marin Showcase Theater in San Rafael on September 9 and 16.