FlyerTalk Evangelist
Join Date: Nov 2000
Location: Nashville -Past DL Plat, FO, WN-CP, various hotel programs
Programs: DL-MM, AA, SW w/companion,HiltonDiamond, Hyatt PLat, IHF Plat, Miles and Points Seeker
Posts: 11,072
I would also guess some missing spots are to more people have the premium credit cards and getting free A1-15 boardings. We have done that on some flights. On one flight we got a2 and a3. And there for around 6 people behind us in the A1-a15. I have to assume they bought upgrades right after we did. That would leave their spaces open as well.