Based on an experience I had several weeks ago, I'm puzzled as to the exact priority ranking for standby travel.

I arrived at the originating airport early, and used Easy Check-In to check in to my original flight and to stand by for the earlier one. I wasn't offered the $25 confirmed standby at this time. (If it matters, I think I was on an M fare)

At this point, I think I know where I am on the standby list - below F passengers, below any non-rev UA employees, below passengers who have already had delays and/or risk misconnects, and below UGS - but above 1P's, 2P's, non-status passengers, and 1K's who bought an H or lower fare. (If I am wrong, please correct me)

There were major delays - both weather and mechanicals. Several flights were canceled.

Had my original flight been canceled, would my priority on the flight I was standing by for have gone up? Does it matter if the "earlier" flight departed after the original flight's scheduled departure time?