Originally Posted by
username
I believe "Upgrade elite->biz Z" also works as Economy -> Business for Star Alliance upgrades since Elite does not exist in the Star Alliance award structure.
Looks like I was wrong to assume upgrades come from the same inventory as awards. Z vs. I respectively.
So perhaps I was lucky that there was Z space after I bought my tickets, having previously checked that there was I space?
Question then: which of the two pots is normally bigger?