Call it the Kentucky Derby Playoffs. Churchill Downs is upending its 139-year-history of using grade stakes to determine Derby entries and adopting a points system to set the 20-horse field for next year’s Run for the Roses. Officially named the “Road to the Kentucky Derby,” the new system will be implemented this fall through points accrued in selected preparatory races. Churchill’s management is hopeful that the points system will get fans more geared up for the race. “People understand the Derby is the Super Bowl of racing, but they don’t understand what the ‘league’ structure is and what the series is to get there,” track President T. Kevin Flanery said in a statement. Points will be accrued in 36 races, as opposed to 185 races that previously factored into selection.