So it is clear that the seatmap is not always accurate and that unassigned seats don't necessarily mean upgrade space, some might be sold but unassigned. However, what happens when the seat map shows X available seats but expert mode shows Y available seats where Y > X? I know that on certain configs like 777XC, 9AB are always blocked, whether it's ORD-PVG or ORD-DEN but on the DEN legs, those seats are sold and on the PVG leg, they are pilot crew rests. But what about on the 744 in F, for example, where no seats are reserved? What does it mean then? Thanks for the input.