“A Natural from the Start: The Life and Time of Jimmy Winkfield, International Horseman” celebrates the jockeys in the early years of Churchill Downs. It’s a reminder that some of the best jockeys in Derby history were African-Americans. Winkfield is the headliner, but the show also includes Isaac Murphy and Willie Simms. From 1875-1902, black jockeys won 15 Kentucky Derbys (Winkfield was the last African-American to win). Murphy won the Derby three times, the first jockey to do so. He also has the distinction of winning the most races in history and was the first jockey inducted into the National Museum of Racing and Hall of Fame. Simms is famous for introducing the American style of riding.