From The Indianapolis Sun, Monday, May 26, 1913: Auto polo, the most strenuous expression of sport, is regular polo played with automobiles. Play is on a field, 300 feet by 200 feet, with two cars on a side, manned by a driver and a “mallet man,” competing for five ten-minute periods. An air-filled leather ball, eight inches in diameter, is placed in the center of the field. At the signal the cars dash toward the ball from opposite directions at tremendous speed, with their motors popping, spitting fire, and the wheels tearing the earth. A referee in a fast car follows every play. The Automobile Club of America conceived the happy idea of combining automobile racing and polo with specially constructed, high powered cars. Games will be played at Washington Park, Wednesday, Friday and Saturday.