Derby Down at Arlington Park May 2, 2012 Horse racing season is upon us and Arlington Park Racetrack opens just in time for the Kentucky Derby! Celebrate opening day on Friday, May 4th with some awesome specials: One hot dog & either a 12 oz. beer or 20 oz. soda is only 50 cents and Mr. D’s Sports Bar will have $2 beers and ½ price appetizers, you just can’t beat those prices! Gates open at 11:15am and the first race is at 3:00pm. General admission is free and preferred parking is only $5.