My last United flight of the year is in the bag, so it's time to sit back with a cup of spiked cocoa, listen to Christmas music, and take care of important business like...

...calculating my exact CPU percentage for the year! Yes, folks, this is probably the most important thing you'll read today. Like you, I keep a big ol' spreadsheet each year with all of my flights listed on it. Its most important function, of course, is to track progress toward requalifying. But since I've got all that data, I also keep track of upgrades, etc. I mean, given how much FTers complain about their upgrade percentage, I gotta keep track of mine!

However, I've realized that there are some tricky ambiguities in exactly how to calculate this. So I'm consulting the experts -- you!! -- to see how this should be done. Read on, and then tell me what I'm doing wrong.

First of all, there's clearly no single statistic to rule them all. I calculate the following metrics:

1. CPU percentage (on CPU-eligible flights).
2. Overall upgrade percentage (on upgrade-eligible flights).
3. Percentage of all flights flown in F/J vs Y.
4. Percentage of flight miles flown in F/J vs Y.

FWIW, as a 1K located at a non-hub, I'm between 62% and 69% on all those metrics -- according to my current methodology. But those numbers are influenced by some tricky edge cases.

So... some questions for y'all. (None of these are hypothetical -- all of them happened to me this year).

1. IRROPS. If I get an advance CPU but then get rebooked on another flight in Y and miss the CPU, does that count as a failed CPU? What if I get the CPU on the new flight -- does that count as one success, or two? What if I I'm CPUed in advance, but get rebooked on a single-cabin flight? What if I'm booked on a single-cabin flight, but then get rebooked at the last minute on a 2-cabin flight but don't get the CPU (does that count as a failure?)
2. VDB. If I get an advance CPU, but then take a VDB and miss the CPU on my rebooked flight, does that count as a failure? What if I get rebooked on a single-cabin flight? What if I get rebooked in Y on AA or DL? And what if I get rebooked on AA/DL in return for a $500 voucher, and buy an upgrade on the AA/DL flight for $100?
3. SDC. If I get an advance CPU, but choose to SDC to a different flight and fly in Y, is that a failed upgrade? What if I'm not upgraded, but SDC to a new flight where I do get upgraded?
4. RPUs/GPUs. Obviously, P.S. and international flights aren't relevant to CPU percentage. But what about CPU-eligible flights where I apply a certificate? Do these count toward CPU percentage at all? What if I obviously would have gotten upgraded even without the RPU? Or what if I miss the upgrade despite applying an RPU?
5. Y/B/M-ups. Should these be counted as "CPU" at all? And does it matter whether I booked the Y/B/M fare, or got rebooked into Y due to irrops?
6. Companions. If I'm flying with a companion, and my companion gets upgraded too, does that count as "extra credit" for my CPU percentage? What if I decline to split the reservation, but might have gotten upgraded after checkin if I had split it? What if I get upgraded but my companion doesn't and I decline the upgrade?

I feel like all of these are at least a little bit ambiguous (although I'm equally sure that somebody will declare that the answers are blatantly obvious). But I'm curious if y'all have thought about some of these, and if so, what you do when calculating upgrade/CPU percentage.