I apologize if this is the wrong forum, but I'm trying to figure out the whole VDB thing. Got expertflyer and looking at the availability of flights. Is there a "tried a true" class to look at or is it random? Can multiple classes (ie. S, N, Q, O) take up the same seat?

Thanks guys

You signed up for EF just to increase your chances of booking a flight that will need volunteers?

The free trial.. just trying to learn

Really, to play the VDB game, you need to book a cheap fare months in advance. This means using some intuition, like you know the Wednesday before Thanksgiving will be full flights. The Friday before Memorial Day or Labor Day or other 3-day weekends may have high loads. Sundays in March will be crowded with people returning from Spring Break, etc.

When it is far enough in advance to get cheap tickets, looking at ExpertFlyer fare buckets will not be very useful.

But to answer your question, the only thing you need to look at to predict VDB in the short term is F0 J0 Y0.

If there are only ten seats left on the plane, then the airline can sell those same 10 seats in all booking classes. Like I search for DFW-DCA tomorrow, and I can see this on AA1530:
F1 A0 P0 Y7 B7 H7 K7 M7 L7 W7 V7 G7 S7 N7 Q7 O7

All this tells me is that F has one empty seat (F1 A0 P0), and there are at least 7 coach seats left. AA is willing to sell at least 7 of those coach seats for cheap: (Y7 B7 H7 K7 M7 L7 W7 V7 G7 S7 N7 Q7 O7) In reality, if AA has 7+ coach seats for sale at deep-discount "O" or "Q" rates, the flight is probably pretty empty, and since the departure is tomorrow, I can check the seat maps and verify on the seat map.

On the other hand, I see this for AA176 tomorrow:
F1 A0 P0 Y2 B2 H2 K2 M2 L2 W2 V1 G0 S0 N0 Q0 O0
That tells me that the flight is pretty full, but they're still willing to sell two coach tickets and one F ticket. This one could conceivably go oversold, but AA is pretty good at revenue management. They wouldn't be willing to sell those 2 coach seats for cheap-ish (V or W) if they were in danger of having to pay $400+ to bump someone. So my guess is it will go out exactly full but no bumps.

If it looked like this:
F1 A0 P0 Y2 B0 H0 K0 M0 L0 W0 V0 G0 S0 N0 Q0 O0
Then I would say there's a chance it could go oversold. They are willing to sell one F ticket and two coach tickets at full price, because even if they bump someone, they will make a net profit.

If it looked like this:
F0 A0 P0 Y0 B0 H0 K0 M0 L0 W0 V0 G0 S0 N0 Q0 O0
Then it's almost certainly oversold or else there is an irrops situation.

Fantastic! This is exactly what I was looking for. Thank you very much for the information!

As this doesn't have anything to do with Mileage Runs as far as I can tell, I am going to move this to Travel Buzz. You can follow any further discussion there.