They pull apps from all stacks. The short stack just gets more taken from than the normal stack. The highest points getters rise to the top of their respective stacks, therefor you can be selected from either one. You just have a greater chance in the short stack. I have heard that 70% get pulled from the short, 30% from the normal stack, but I can't confirm this. If they plan to hire 1000 pilots this year they will have to select approximately 2000 to the interview process. At that rate they will have interviewed every applicant in 5 years. Considering all the other companies are likely hiring from that same pool I would say within the next 3 years basically every applicant will have had the opportunity to interview. Stay positive and keep building the resume! Keep updating the app as well!