CX has been very consistent in the way that is uses the methodology that Norse_Aztec describes above, and combined with the fact that I have never had FF mile-earning issues with them, I am now more and more checking the CX schedule before I check the SQ schedule. If CX has a useful flight, I just have the flight booked.

CX then treats me nicely, often pushes me from J to F, and always awards the correct number of miles. Plus HKG is a good place to stop en route.