UDUstats says that 1k's clear 82% of the time, even use UDU. And that's probably conservative since people are presumably more motivated to post there after failing to upgrade. those are actually pretty awesome, when you consider that you didn't actually pay for first or even apply an instrument.

However, I'm not sure how far back those stats go and I don't see any way to check only the recent months. It might be much lower now. That's been my experience (I went from 95% UDU clearing in years past down to more like 60%). I don't feel that I really understand why.

I don't get why the UA+CO merger means that there are twice as many elites per flight, since there are (approximately) twice as many flights. The only thing that would actually increase the # elites waitlisted per flight is if, before the merger, there were lots of UA elites on CO flights, and vice versa, that didn't appear on the upgrade list, but now do. But I doubt that accounts for much (maybe <5%?).

The Jan/Feb bump might account for a little bit (maybe 10-15% turnover year to year?), but I don't recall much of a problem upgrading Jan/Feb in previous years.

The big change, for me, will be the new prioritization rules (by upgrade instrument before status), but I thought those have not gone into effect yet.

P.S. UDUstats should add "year/month" to the search menu, and perhaps add "final position on waitlist if you didn't clear" to the data entry page.