I'd point out that OP's question was answered in the first reply:

OP also asked for anecdotal experiences:

So, what are you on about?

Getting back on track, OP asked if he/she could book other times to increase chances.

edit:
Kacee pointed out that my anecdotal experience is wrong and provided this useful tip:
end edit

I'd anecdotally, from personal experience, say that this doesn't increase odds and it would probably be very difficult to get any sort of stat on this outside of tapping in to United's stats directly. I think when you're traveling to a vacation destination, non-business related type destination, odds of upgrade increase quite a bit but OP is asking about SIN so I'd say that's out the window.

You're wrong.

If you have flexibility in your schedule and are willing to put in the effort to find the right flights,* GPU upgrades can absolutely be confirmed. That's my experience and that of many others in this forum. There's an entire thread on that point. GPU Upgrade Success 2017.

I feel for the business travelers who have to fly specific flights on specific days, because that's where GPU become a low odds proposition.

This "GPUs are worthless" debate has been done to death and it's just really old hearing the same old complaints over and over.

*And so to further answer OP's question, you need to spend time searching, check the loads on specific flights (United Flight Status Tool), identify your candidates, watch them and see how the loads change, try to book into open R, but go ahead and waitlist if the inventory movement suggests R is going to open.

That's great information, thanks! I'll update my previous post with this - Not sure why you didn't reply with this in the first place? (also being pedantic but, my anecdote is not wrong).

OP Asked specifically for anecdotal experiences. To me that reads: "Story Time!". Possibly, OP didn't want to read through hundreds of pages of posts that might also tangentially wander to gather his information.

In the end, I'm just not sure I understand your complaint on this thread. This is a forum where discussions occur, not a static users manual, you can read United's pages for that information. Airline rules, regs, successes, failures, they're a living thing. Their policies change regularly (and by agent and airport and hundreds of other factors) and an experience from 6 months ago might not even be relevant today. The number of times I search for FT threads on a topic and end up with hundreds of pages from years ago frequent. It can be hard to know if that information is still relevant or worth even wading through. I'd hate continually discouraging people from asking questions just because something similar has been discussed somewhere else.

Now that this is sufficiently off topic, I'll refrain from further commentary.

The first reply mentions buying a higher fare. I would focus #1 on just finding R availability. If R is available, there is no need to go above W. This means considering different routing and times.

If you are forced to waitlist, ofcourse you can buy the highest fare you can but that isnt always an option. If you are close in, its worth checking the inventory (or even seat maps). If the C looks empty, you should have a better chance than if its completely full.

If you aren't flexible at all, then there is nothing you can do to increase your chances. The only think you can do is monitor R like a hawk and call in if it opens up.

As far as buying a higher fare, I think one step above minimum (usually V over W) is all that has a value proposition. The 98% of 1Ks who don't read FT are not going to be buying V fares just to bump their GPU chances.

Thank everyone for posting their tips or anecdotal evidence. I understand there must be a lot of people who are frustrated with their experiences of not getting their GPU's cleared. It's a system that isn't very transparent and involves putting in more money and sometimes not getting anything in return. So the complaints are warranted.

In the meantime, I have gone with the confirmed ORD-SIN flight upgrade on the pmUA 777 2-4-2. But will gamble with my chances from SIN-SFO. And taking the tips of looking for open R space periodically, looking at flight load changes for similar departure days, and praying to the GPU gods but keeping expectations low. And maybe in the future buy up to a higher fare than W like V or Q.

Currently the return flight has many unassigned businessfirst seats, more than half empty. But expect them to fill up as the date gets closer.

Any more anecdotal evidence, tips, or strategies would be appreciated and helpful for future GPU waitlist gamblers.

Fly LH.
Pray.
UA keyboards don't contain the letter 'R'.

OK, I've tried to search this but came up with nothing. What exactly is a P class fare? Is it a new fare class below Z? Supposedly the lowest fare type for Biz. I'm asking cos I don't recall seeing it before.

Not new. P is the lowest discount, non-refundable Business fare (if available).

So "pray" becomes "pay"?

Well played.

Badum tss...

David

THIS. For our private trips, we try to look for days/routes where confirmed GPUs are available. If they aren't, then we use miles to just "buy" a business class ticket on the long international flights.

There are a lot of times that I would be tempted to 'buy' and upgrade with miles for the delta in miles between economy and business- especially when there is biz saver or even standard offers. Just to not have to do the W Hail Mary and waitlist. If they are willing to exchange a biz seat for all the miles, why not offer this? You can upgrade for cash+miles, for a much lower mile total, but that is just like a GPU, correct?

This is one of the primary reasons I abandoned my former annual quest for 1K. GPUs are becoming increasingly worthless.