Sunday Before The Daytona 500
First, the front row is locked in based on qualifying time trials that happen on the Sunday before the Daytona 500. Each driver gets two laps alone on the track to post their best speed.
The top two drivers from that qualifying session are locked in and will start the Daytona 500 from the front row.
On Thursday before the Daytona 500 the Budweiser Duels twin qualifying races are lined up based on last weekend's qualifying speeds. These two 150-mile races will set the final starting lineup for the Daytona 500.
Drivers that qualified in odd-numbered spots run the first race to set the lineup for the odd-numbered (inside line) starting positions and those in the even-numbered spots run the second race to set the lineup for the even-numbered (outside line) starting spots.
The top fifteen drivers from each duel other than the driver that has already clinched a front row starting spot will then qualify for the Daytona 500 in rows two through sixteen.
Speed Still Counts
The next four starting positions (33, 34, 35 and 36) go to the four fastest drivers who did not lock in a starting spot during the Budweiser Duels. These positions help ensure that a fast car who crashed or broke during the Budweiser Duels still has a shot at the race.
After the top 36 starting positions are set by the Qualifying and the Budweiser Duels the provisionals are set by the rulebook.
There are six provisional starting spots available to the next six drivers highest in car owner points from the previous season that have not already qualified through the time trials or the Duels. These cars will be lined up based on owner points and not by speed.
Rounding Out The Field
This leaves one spot remaining for the past Champion's provisional.
This final starting spot goes to the most recent former Sprint Cup Series champion that has not already clinched one of the other forty-two spots. If there are no former Champions who are not already in the field then NASCAR will add a seventh provisional starter based on car owner points to the six previously added above.
It is a complex process but it is part of what makes the Daytona 500 such a special event.