Sorry if this question is too elementary, but how do you check for R availability on a flight I've already booked? When I do an advanced search for the route and day I'm booked, it tells me that R is an invalid fare class.

Currently GPU waitlisted ORD-NRT-ICN.

You have to turn on expert mode in the UA MP user settings area - and then search each flight segment separately to avoid issues with married segments. In your example - search ORD-NRT, not ORD-ICN...

With expert mode turned on you will see that the words "fare class" are underlined - click that link to see a box open with the fare class buckets and look for R - it will show something like R2 - meaning that there are two seats in the fare class available.

That is terrific--thank you!

They can screw everything up at the same time

i guiltily admit i've been a sniper lately, esp during the T-24 window between those cleared automatically and those at gate

Another sniper in the woods....

Locked and loaded! But don't worry, I'll snipe responsibly.

then you will be one of few that do....

It is pretty much of "its all about me" scenario.

I don't anticipate being a day-of-departure sniper, at least. Otherwise...we'll play it by ear.

On a related note, has R availability always been this poor? I've only been using GPUs for the past couple of years, but last year, all attempts cleared at booking. By comparison, my 2014 attempts have yielded the following results:

ORD-SFO-HKG: WL-->Clear

(ORD)-SFO-TPE: Clear at booking (no UG on domestic segment)

TPE-SFO-ORD: WL-->Fail (SFO-ORD cleared at gate but GPU was redeposited)

ORD-EWR-DEL (not yet flown): Both segments WL-->?

(CGK)-NRT-ORD (not yet flown): Cleared at booking (CGK-NRT segment not on United metal so obviously UG not possible)

ORD-NRT-ICN (not yet flown): Both segments WL--?

I realize that there are a number of variables at play, but still seems like they're tightening R inventory.