Joe K
About the only thing I have been able to figure out is when a flight is completely sold out.
You can tell if the flight is sold out if you go to the awards page and see the freedom awards are unavailable (this assumes you are not trying for a blocked out date). Or, if you have a CP, the CP is not available for a given flight.
You can also tell if a flight is sold out if both the BS fares and the anytime fares are unavailable....
However, stuff happens. Passengers could fail to show up at the gate for any given flight. On the other hand, you could have a flight that looks like it has availablity and a crew from United hops on board.... or, a flight has a mechanical and all the passengers get moved over to your flight... et'c.
We ask the GA if we are really curious.
