Originally Posted by RobOnLI

Checking each flight separately is the far more accurate means of seeing availability. The reason the flight availability changes when you search BKK->DTW (without the stop in NRT) is because one segment can't possibly have more seats available than the lowest number of seats of any segment of the itin. Therefore, if BKK-NRT has Y9 B9 but NRT-DTW only has Y3 B3 then the flight availability tool will show the lower of the numbers.

I'd say with the flight loads looking as they do, there's a chance of op-ups happening on the flights (especially on the 21st where it's J9 and Y0). And yes, you absolutely can bump yourself over and over again. Good luck and please report back to us and let us know how you make out with either an op-up or bump.

-RM