After the Top 2 positions are locked in, the next 30 places of starting grid of the Daytona 500 is set by the finishing order of these two races with the top 15 (excluding pole winner and outside pole) making up the next 15 places on the inside and outside lanes respectively.

After the Duels are completed the four fastest non-qualifiers by time and finally the six or seven (if no past champion's exemption is needed) highest-earning teams in points (from the previous season's standings) not in the race yet advance (also set by time), and the starting grid for the Daytona 500 would then be set.

For 1968, the races were scheduled for 125 miles (201 km) each, but were cancelled due to rain, and the starting lineup for the 1968 Daytona 500 fell back on the timed laps.

For 1972, NASCAR's modern era commenced, so races were required to be at least 250 miles (400 km) to be included as official points events.

ABC first aired the races in 1971 as part of Wide World of Sports highlights show.

With the introduction of restrictor plates in 1988, the resulting reduction in speed and fuel consumption again allowed drivers to possibly complete the race without a pit stop.

Under the current charter system, because all chartered entries are guaranteed entry to every race of a season: The arrangement of the Duels under the charter system notably cost Ty Dillon a starting spot in 2021 when Ryan Preece beat him during the Duels as Dillon, despite still finishing in the top-10, did not have a fast enough qualifying time compared to his non-chartered peers.