Originally Posted by bosman
While it's been a while for me as well, I remember many situations that suggested there was absolutely no rationale to the groupings at all. One LAX - BOS flight I was group 5 and the person sitting next to me was group 2.
.... which is what you'd generally expect (at least that you were different groups).
If I was dividing up an MD80 coach cabin into 5 boarding groups, I'd take -
1. Back part of the plane, window seats.
2. Back part of the plane, middle seats.
3. Back part of the plane, aisle seats,
4. Front part of the plane, window and middle seats.
5. Front part of the plane, aisle seats.
.... or some such arrangement. With a 2-3 configuration, it's perhaps harder to come up with logical groupings than in a 3-3 configuration. Compound it with including elites in Group 1 and, perhaps, not splitting up people travelling together and it gets a bit 'random'......
Conceptually though, it's presumably pretty simple - you want the people in the window seats at the back of the plane to board first and the people in the aisle seats in the front of the plane to board last.