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?