If the Indianapolis 500 is known as “The Greatest Spectacle In Racing,” its qualifying procedure deserves the title of “Greatest Mental Gymnastics Required To Set The Field Of 33.”

For those who want to follow along on Saturday and Sunday as 35 drivers vie to earn one of the 33 spots available for the 105th Indy 500, here’s a cheat sheet on how the weekend will go:

1. Saturday morning, the field will be split into two practice sessions from 9:30-10 a.m. and 10- 10:30 a.m. ET. It’s an opportunity for everyone to go out and get a feel for a few changes, but there’s rarely a point where free space is available on track to lap without receiving an aerodynamic tow that would give a false read on the car’s qualifying potential. As a result, some teams elect to skip the practice session.

2. Starting at 12 and running through 5:50 p.m., all 35 drivers are guaranteed at least one qualifying attempt. A blind draw, done Friday evening, sets the qualifying order, and once that list has been run through, drivers are free to make additional qualifying attempts.

3. But those extra attempts could involve a decent wait if a lot of drivers line up to try for a faster average speed over four laps. This is where IndyCar adds some complexity to the decision-making process. Teams can pick between two lanes: Normal, and Fast.

4. In the Normal lane, drivers are allowed to make new runs without having to erase their original (or improved) qualifying speed. It’s the safe option, but could limit how many extra runs can be completed if there’s a long line at the drive-through window.

5. The Fast lane is where the series brings a bit of drama to the rerun scenario. For those who want to skip the Normal lane and go to the front of the order, the Fast lane can be used, but it comes with a requirement to void your qualifying speed. Skipping the line might be considered as the clock winds down toward 5:50 p.m., but if a driver’s slow or had an issue while on track, picking the Fast lane and getting it wrong during the run could be a dangerous roll of the dice.

6. Assuming all 35 drivers are successful at completing one qualifying run, IndyCar will split those 35 into three categories once the checkered flag waves. The nine fastest drivers are locked into starting inside the top nine, but aren’t finished with qualifying. The drivers who filled P10-P30 are locked into position and are finished with qualifying. And like the Fast Nine, the drivers from P31-P35 aren’t finished. Speeds for P10-P30 are official and permanent. For the Fast Nine and P31-P35, their speeds are voided once Saturday is done.

7. Altogether, every team has one goal on Saturday: Make it into the top 30.

8. The Fast Nine and Last Chance Qualifying groups take priority for most of Sunday, starting with a 11-11:30 a.m. practice for the P31-P35 LCQ drivers and a 11:30 a.m.-12 p.m. practice session for the Fast Nine. Each Fast Nine entry will receive one new set of Firestone tires for the 30-minute practice, and a new set for their qualifying session.

9. From 1:15-2:30 p.m., LCQ qualifying will fill the final row for the Indy 500 with P31-P33 and the bumping of P34-P35 taking place. No new tires are provided, and LCQ drivers can make as many attempts as they want during the 75-minute session.

10. From 3:00-3:45 p.m., the polesitter for the Indy 500 and starting order for the Fast Nine will be set, with each driver guaranteed one run.

11. The close to the day — and the end of on-track action until Carb Day on Friday, May 28 — is brought with an open practice session for the field of 33 from 5-7 p.m.