In particular, who goes into zone 2 and zone 3?

On two recent US domestic flights, we got boarding passes for zone 3.

When zone 2 was called at boarding time, nearly everybody in the waiting
area got in line, leaving just a handful of us poor zone 3 schnooks
behind.

We bought our tickets well in advance directly from Delta's Web site,
checked in on line, printed our boarding passes at home and we're both
Skymiles members.

Since the zones no longer have any relation to where you're sitting
(other than first class and economy comfort), the main drawback to being
last to board is the lack of space in the overhead racks.

I asked the gate agent if she could explain and she said she had
absolutely no idea how the system worked.

--
St. Paul, MN