I'd like to know how United decides to clear free upgrades. I fly DEN-MCI (Kansas City) regularly using "B" fare tickets. About 50% of the time my upgrade doesn't clear until boarding time. About 10% of the time, I sit in coach. I'm a 1K, Milliion-Mile Flyer. Who *are* these people that are clearing first class upgrades ahead of me? I know that some of them aren't 1K's, because I've sneaked peeks at their boarding passes.