Originally Posted by Deathray

Speculating: when an upgrade clears at R0, one of three things is occuring:

1. There is a hidden bucket that has availability and clears the upgrade OR
2. The R capacity portion of the revenue algorithm runs and decides there should be more R space and adds it which causes a waitlist upgrade to clear OR
3. A seperate part of the revenue algorithm runs and decides that this particular ticket should be upgraded and does so

My supposition would be that there is a combination of things going on. Having a single, simple hidden bucket seems unlikely from some of the behaviour we have observed where dollar value or revenue vs award variables seem to matter differently. That isn't to say that there isn't a hidden bucket that can sell an upgrade in very specific circumstances when a combination of variables declare a certain ticket as high value.

The distinction between 2 and 3 is more interesting to me. I would lean against thinking that 2 is happening very often because if the main hidden mechanism to clear R0 upgrades is simply to increment R space, I would expect that the cross section of tickets that get upgraded in this scenario would be more random. If R is simply being added, I don't see how they would direct that R space to clear a specific ticket when multiple eligible tickets may be waitlisted (or at least it would force the hidden criteria to be the same as what we know of the waitlist order).