Originally Posted by
bchl
the reason why I've never considered to join AA or QF is the fact that you will need 4 flights each year on their own metals.. So that's why I ended up with CX

With my flying pattern I could never be able to fulfill these needs...
The only OW FFP that seems to enforce the minimum 4 flights rule is BA. AA and QF have the same rule but do not enforce it. However, that may change in future - notice how the AA challenge is now required to be on AA coded flights.