The pilot of a tailwheel-equipped airplane stated that, during the landing roll, the airplane veered slightly left of the runway centerline. To correct for the veer, the pilot applied right rudder, and the airplane subsequently veered right. The pilot was unable to regain directional control, and the airplane continued off the right side of the runway onto soft gravel, which resulted in a rapid right ground loop. The left landing gear leg fractured, and the left wing and elevator impacted the runway surface, which substantially damaged the left aileron and fuselage. The pilot stated that he had no experience flying this model of airplane on wheels. According to the airplane owner, the airplane’s rudder and brake system was unique and could be difficult to operate. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.