Originally Posted by G-CIVC

I think this means there are two 'versions' of op ups:

1) A ton of people OLCI, the flight is clearly overbooked (in some cabin). Then the system performs cabin roll automatically before airport counter opens. Op up priority goes like DM GO SL GR ID etc. OW elites can only try their luck at the airport.

2) The flight is overbooked number wise but the situation is not clear until it is under airport control. At some arbitrary time within that (e.g. T-90) it is clear that the flight is overbooked. Then airport control does op ups according to the order we are all familiar with here.

I think I can claim that 1) has happened to me before. I was on a flight, booked in PEY, that seemt oversold (something like W3 R2 E0 Y2 B1 H0...). J is very light. The seat map was totally filled in PEY and Y at T-72 as those Xs started popping up. I OLCI as normal and think hmm..., should be ok when at airport. (I almost get 'regularly' op up'd on this flight from PEY to J.) Then at T-8, the morning before I set off, to my surprise PEY became very empty (10+ seats), and a corresponding amount of seats is filled in J. But, no dice for me. I only snagged the last op up (and the only at-airport op up) because they sold a discounted counter upgrade for a Y pax into PEY. Later in the flight, I saw in the J seating plan, there were DM GO SL GR and ID in the op up list.