Help with seat availability
 

I know that there are explanations for seat availability by fare class showing less than a count of seats available on the seat map (for example passengers with tickets that have not as yet selected seats).
But how about the opposite situation......fare class showing more available seats then the seat map.

Here is a specific example. Flt 35 SFO-OGG on 7/31

Fare Class F9

Seat Map 7

Tried searching on this and couldn't find an answer. TIA

Could mean a couple of things (off the top of my head):

1) UA is overselling that cabin due to expected no shows and/or double bookings.

2) There may be seats blocked for assignment closer to/on day of departure.

Realize that if there are some folks interested in purchasing full fare F tickets, UA would be happy to accommodate them even if the flight ultimately is oversold in F and IDB/VDB scenarios present themselves. The extra revenue for the full F purchases ($3227) should easily compensate for the IDB/VDBs, and, of course, there's no guarantee that everyone assigned seats in F will actually show up for the flights.