Chicagoist isn't usually one to play the ponies, but then it's not every day that the horse racing world is focused on Chicago. On Saturday, Arlington Park will host the 25th Arlington Million, the largest annual stakes race in Illinois. Among the field is last year's winner, Tin Man, with 3-1 odds. The nine-year-old is looking to defend his title against this year's favorite, After Market. The favorite at 2-1 odds, After Market is trained......