Early check-in is such a roll of the dice, even if you have good hotel status. Naturally it hinges on occupancy rates and your room type being available. I'll usually email the hotel a day or two before arrival to ask if they can note my early check-in request on their system, and when my flight lands I'll phone to see if early check-in is available now or to get an estimate.

For example, my MO on BA16 SYD-LHR is to head for BA's T5 Arrivals Lounge (because I'll want a proper breakfast and to relax a bit after my long flight) and call the hotel from there. They usually advise that yes, they can accommodate me at say 8am-9am, so I can then relax at the Arrivals Lounge with a mind that's at ease, and plan out my morning.

A few times I've arrived at a hotel and no rooms available until much later, even 'normal' check-in time, so they'll let me visit the spa or gym or pool area where I can at least shower and change into fresh clothes. Everything is better after a nice shower, in fresh clothes, and with a good coffee in hand

Of course, we probably all know somebody who says "why take the risk, just book the hotel from the day before so you can actually check-in at 6am or whatever." Well, yes, nice if you have the money for that!

Then again, I actually did that last year for a stay at HK's East Hotel, they had a "book three nights, get four" deal, my planned stay was three days/nights so I booked from the day before my arrival. It was great to be able to head straight off CX138 to East, check in, shower and have the included buffet breakfast.

But, yeah, most of the time we are all going to rely on the good fortune of snaring an early check-in.