Originally Posted by
Kmxu
If you see a long upgrade standby list (excluding non-rev, they also appear on a separate standby list) and there are very few first class seats remaining, your chance for upgrade would be probably slim. If you decline for upgrade, your record with partner will not be split after check-in.
Right. The only way to get upgraded at the gate is to split your reservation, so the screen will ask you if you'd like to waitlist for an upgrade. If you do not want to be split, you have to decline that option, which means you'll never go onto the visible upgrade list, and you'll be removed from the hidden upgrade list that they process prior to the gate. That's why I recommend checking in at the airport for flights where you haven't been upgraded and don't want to split.