Ups and downs of the ins and outs of Duel qualifying

Ups and downs of the ins and outs of Duel qualifying: "Both of Thursday's Gatorade Duel 150 qualifying races for Sunday's Daytona 500 lived up to the old-school hype as the fortunes of the 18-car go-or-go-home group shifted in the final laps, in a pair of races that totaled the closest margin of victory in their 52-year history."