I was on a recent flight where shortly before boarding there were a fair number of Comfort+ seats open (probably about 35% to 40%) and only one person was listed on the upgrade list. They were shown as having a seat. There was also a good amount of passengers on the stand by list when all seats in the main cabin were assigned except for 1.

I saw people on the stand by list get assigned seats in the main cabin, which I am guessing means the person originally sitting there got moved to Comfort+. Right as boarding started all seats (according to the app) in Comfort + were assigned and according to the gate television screen most if not all stand by people were assigned seats.

If everyone who falls into one of the 7 priority levels on the upgrade chart already have an upgrade, there are seats open in Comfort +, and there are still people on the stand by list waiting seats, what criteria is used to determine who to move into Comfort + to free up their seat for a stand by?

They probably just give the standbys the C+ seats at that point rather than shuffling other pax around. Also the standbys that normally clear last are usually non-revs and they can be seated in whatever best seat is left available (even FC if there are still open seats).

They will give the standbys Comfort+ seats before they move passengers not eligible for an upgrade to Comfort+. This is mostly since it's a bad customer experience to unilaterally move a customer's seat (they might be sitting next to another passenger on a different PNR) and at the time the standby list is cleared, the gate agent doesn't have time to call people up and ask. Delta employee non-revs are also eligible to be seated in the highest cabin with available seats once all revenue customers are accommodated, which in many cases will be Comfort+.

one time, the gate agent moved up passengers with infants or disabilities even when I am on upgrade list for C+. I ended up one row behind C+

I suspect those passengers got their previous flights cancelled and moved to this later flight.

Often, the standbys are Delta employees flying NRSA (non-revenue). They would get the open seats in C+ (non-medallion paying pax are in the back unless the flight is oversold or are in an IRROPS situation). This is why you can't count on a middle seat in C+ going out empty; at the last moment, DL will give that seat to an NRSA standby who wasn't on any gate display standby list).

Interestingly, some DL gate agents don't get around to upgrading medallions from main cabin to C+, and that such pax who want the upgrade to C+ have to go up to the gate agent and ask for it.

The 1st row in C+ is block as disability accommodation for those with certain qualifying disabilities. (C+ is still part of the main cabin for this purpose)

NRSA are on the gate display standby list.

Yes, also in the app.

I have seen cases where main is full but passengers with basic economy tickets have been assigned C+ as the last open seats.

Also, some pax either only ask for an F upgrade (but not C+) and others will ask for C+...but not for a middle seat. So you might well have elites who have essentially asked *not* to be upgraded (since MC with an aisle vs C+ in the middle might effectively be a downgrade for some folks with long legs).

I believe this is why customers in BE used to get C+ from time to time. GA just cleared them into C+. Not sure if this has been fixed but for a while it was actually a problem where GAs would clear people without a seat assignement before clearing the upgrade list so BE would sometimes get C+ over someone on the upgrade list. Not sure if this has been corrected

I read the title (Upgrades after the 7 levels on the priority chart) and thought:

• First Level: Limbo - Standby/No assigned seat.
• Second Level: Lust - Oh they got upgraded, me too.
• Third Level: Gluttony - Take the upgrade regardless of others traveling
• Fourth Level: Greed - I need that upgrade.
• Fifth Level: Anger - Damn they got upgraded.
• Sixth Level: Heresy - No one needs an upgrade.
• Seventh Level: Violence - Trip them as the board, then in the confusion take their seat.
• Eighth Level: Fraud - Use your last boarding pass.
• Ninth Level: Treachery - Change the seat numbers.