I pretty much fly transcons exclusively, so upon first learning about the upgrade benefits of Medallion status last year, my eyes glazed over in fantasy visions of sitting up front on these long-ish flights. As an FO last year, though, all successful upgrades were confined to short flights only, and I struck out on every single transcon.

I'd like to increase my odds for an upgrade on these transcons, and can fly any day of the week and generally at any time. ExpertFlyer's ability to check the V bucket helps a lot, but I'm having trouble making sense of the wide swings in V availability and what they might mean for actual upgrade chances.

For DL 1781 LAX-TPA during the week of 1/21-1/27, for example, the V bucket looks like this: 0 0 0 7 4 0 1. How strongly do these numbers indicate the actual upgrade chances?

Well, obviously, Thursday and Friday will be easier for that week. I'm not sure what you are asking, exactly.

I would suggest a bit of research. Pick a transcon that you fly regularly and check all the flights for a given week before and after the 2 day mark. Just keep notes, and by the end of the week you will know which flights to choose next time.

Generally I have good luck on Saturdays and horrible luck on Thursdays/Sundays/Mondays.

What it means today is that if you bought a Y fare ticket now, you would be upgraded immediately on those flights with V inventory.

Just as an FYI, I usually get about 50% success, as an FO, on ATL-SAN or SAN-ATL. Just got it on 1/2.

Sorry for the poor phrasing on the original question...I'm trying to get at a subtle facet of V availability that's difficult to put into words. Let me try again:

In my original example that is three weeks from now, the Mon Tue Wed flights are all V0, while Thursday is V7. It appears that Delta expects the forward cabin to sell well most of the week, but there's a huge change on Thursday for some reason.

Does this mean that the Mon/Tue/Wed flights will have very few upgrades, while Thursday has much, much better chances, or does this high variability tend to even out at the gate?

In short, how much stock should one put in V availability weeks before a flight?

The V bucket might not get updated until last minute. It's Delta goal to attempt to sell as many First Class seats then give them as an upgrade. I have been pretty lucky with upgrades from Delta on Domestic routes and also been pretty lucky with using PMU certificates on International flights. I guess it might be the routes I normally fly but you never know. The more you fly with Delta the better your chances are for an upgrade.

You also need to look at the ratio of F to V. If there are a lot of unsold F seats and no V inventory, then DL expects to sell the F seats - but good news for you if they don't.

As coz said, I would follow the V inventory until close to the day of the flight. You will start seeing a trend as to what is available.

Well, what he is really talking about is advance V availability which still doesn't really affect the OP since he is an FO. Even a lot of V seats might mean that all the PMs and GMs ahead of him get upgrades. Unless he is planning on a full Y fare, in which case he might as well spring for a FC A fare.

Often, V upgrades are only to be had at the airport, even if the FC cabin is wide open. I have had flights for which I failed to clear in advance only to get to the airport, find myself #1 on the GIDS with upgrades available for
sale to the general public on K+ fares.

Short answer to my own question after collecting a small sample size: the number of seats in the V bucket more than a week before a flight mean very little when trying to predict the chances of an upgrade.

The details:
When shopping in advance, I used to look for V7 flights and choose them over flights with less V availability.

But then I noticed that flights showing something like F9 A4 V4 a week out usually ended up full by the PM window with a long GIDS list and no upgrade. Just this week, though, I snagged a gate upgrade on a flight that showed V0 months out, and F0 A0 V0 for a full week before the flight.

So at least for a GM flying between Florida and Socal, the number of V and A/F seats available more than a few days before a flight appears to have little or no correlation between actual upgrades.