The 10-race playoff run for the Nascar Cup Series begins at Chicagoland Speedway Sunday. 16 drivers begin the weekend with the opportunity to race for a championship. Top seeded Martin Truex, Jr. is the defending Cup Series race winner. Hear the race on WBUT 1050am and at wbut.com beginning at 2pm. . All three of Nascar’s top series race this weekend at Chicagoland, with the Truck Series racing tonight.