The pilot reported during the landing roll, the tailwheel airplane "moved left." He added power and attempted to go around, but was "not able to get aloft." The airplane exited the paved surface and ground-looped to the left. The runway measured 8,500 feet long and 150 feet wide, and was dry at the time of the event. The pilot reported he had approximately 1,000 total hours of flight experience, including 100 hours in the accident airplane make and model. He stated he did not know whether there were any mechanical malfunctions or failures of the airplane. A Federal Aviation Administration inspector did not observe any mechanical malfunctions or failures of the airplane. The weather observation taken at the accident airport 10 minutes after the accident included calm winds.