Originally Posted by
Wigg
So a PY fare will give you a better chance than a Latitude fare.
A 25K on an economy fare has effectively zero chance at an eupgrade to TYO, even on an off-peak day of the week in an off-peak month of the year. The OP needs to be buying a premium economy ticket to have any chance at all, and then at least has PY to fall back on if the upgrade to J fails.