CART-based teams boycotted the 1996 Indianapolis 500 in the wake of the formation of the Indy Racing League, and the creation of the "25/8 rule," which they interpreted as a lockout by the IRL and the Indianapolis Motor Speedway. CART teams staged a competing race, the U.S. 500 at Michigan. Participants in the 1996 Indy 500 included several familiar Indy car teams such as Foyt, Dick Simon, and Menard. However, many of the drivers were inexperienced rookies from an obscure range of backgrounds, giving the impression of a field of replacement drivers. The 1996 Indy 500 entrants managed to fill the field to 33 cars, but only one car was bumped (then-unknown Billy Boat), and there was a post-WWII record 17 rookies. The field included such unknown drivers as Racin Gardner (land speed records), Brad Murphey (who was also a former bronco riding champion), Joe Gosek (supermodifieds), as well as Johnny Parsons and Danny Ongais; both of whom had not driven in the race since 1986.