Indy 500 qualifying explained

Here's how the field will be set for the 101st running of the Indianapolis 500:

At the conclusion of Saturday qualifications, the starting field is set, with all entries guaranteed one attempt. 

Due to Saturday's weather delay, all cars must be in tech inspection line by 3:15 p.m. ET and qualifying is expected to start at 4 p.m. Only one attempt will be allowed and the order will determine Sunday's run for the pole. Indianapolis Motor Speedway is prepared to extend today’s activities beyond 6 p.m. to execute first-day qualifying.

In 2017, per INDYCAR's Rule 8.4.8, when there are 33 entries, any car that fails to complete its guaranteed qualifying attempt on Saturday due to mechanical or on-track issues and doesn't make a second attempt will be listed at the back of the field and placed in Group 1 (outside the Fast Nine Shootout) qualifying on Sunday. 

Saturday's fastest nine cars advance to Sunday's Fast Nine Shootout, while positions 10-33 advance and will determine starting order on Sunday, with Saturday's times erased.

On Sunday, all entries must make a four-lap qualifying attempt to determine their Indy 500 starting position, with the Fast Nine taking their turns starting at 5 p.m. ET