For my own education here: I have searched this thread and see multiple references to Delta tier 1/2/3 applicants, but little concretely defining them.

I did attend WAI last year and the Delta presentation there and remember many (but not all) of the criteria Delta prefers, but really cannot remember any mention there of the 'tier' system. Does that system really exist, or is it something invented on APC? If it really does exist, any pointers on figuring out where you fall?