Seat map vs. expert mode
 

I searched briefly but didn't see a thread... I'm guessing this has been discussed multiple times but wasn't sure where. If I've been too cursory with my searching, feel free to let me have it :-)

Sometimes (or even often) flights show a seat map that don't seem to match inventory.
Example: 1/4/2020, UA102.

Seat map shows eleven available seats to choose, but inventory reflects J4. Does this mean seven seat assignments haven't been made but that only four are available to sell? Or are there seven in the upgrade queue? (But wouldn't PZ inventory reflect availability?)

At the end of the day, the question would just be: is it safer to look at inventory or the seat map to gauge upgrade clearing chances?
https://cimg1.ibsrv.net/gimg/www.fly...150849d110.png
https://cimg2.ibsrv.net/gimg/www.fly...93b7708e5a.png

Always look at inventory! If flight is close, you can also check of Y is showing full and there is a bunch of blocked seats, it's an oversell and they will fill those with upgrades.

Flight shows Y3, definitely close to being sold out in the back. Odd though, as we normally used to see Premium cabin inventory and seat maps very aligned.

Inventory always trumps if J is < 9.

It's not odd at all. Y is almost certainly oversold by a considerable amount.

Fair point. So if we look at the upgrade list, it should say xx blocked.

Thanks for the replies.

I didn't think to check Y.

Inventory shows how Y5 B5 M5, which makes me wonder if the two upgrades who have cleared actually booked as Y.

What exactly is the seat map in J showing if it doesn't match inventory?

(And out-of-scope, but why does economy's seat map match inventory even less? There are something like 50 open seats on the seat map between Y and Y+ on UA102 tomorrow...)

basic economy, seats not assigned until check-in?

(though some people have seats auto-assigned T-24/48 on their return leg)

The seat map is showing which seats are available for you to select. The inventory is showing how many seats UA is willing to sell. The two are not directly related.

The difference between the seat map and available inventory can be caused by any or all of :
* Passengers that have not yet selected/been assigned a seat (especially things like tour groups where this is common)
* Blocked seats, due to things like pilot rest seats (in particular on some flights the seat next to the pilot rest seat will be blocked until close to takeoff, and only assigned if it's needed - although that wouldn't be relevant on this config)
* Seats blocked for other reasons, such as being held for potentially disabled passengers (normally released at 48 hours, but not always)
* Inventory in J being reserved due to Y being oversold.
* A willingness to oversell J (in general not done on United, but still possible)

Or potentially many other things.

the seat map is a good way to get a general idea of how full a flight is, but it is no way a perfect indicator - especially in Economy (where things like Economy Plus and Basic Economy come into play), but even in Business.