i try to check in as early as possible every time. i dont go setting my alarm to it or anything, but it can have its advantages. usually not, but why not just check in and get at the top the list of others who are equal to you.

check in time must have had to come in to play on my last iah-pty flight. sold out in F for weeks. after the PC agent reinforced what i have already known for weeks, I presumed to get super drunk in the PC so i could pass on in 5F for the four hour flight.

turns out i got the "beep, beep, beep" as i boarded the plane. as it tuns out i was a little too drunk upon arrival n PTY.

the thing is, you never really know for sure, where you were on the list, who was originally on the flight and who may left the flight for an earlier but are still on the list. and of all those, what fares they were on.

do as much as you can to imporve your chances and every now and then it will work for you. most of the time though, it doesnt really matter.