Upon reading some more in this subforum I believe it is by each individual sector, so if you fly LAX-JFK-LHR they are treated as 2 one-ways.

I have a further question though: is it possible for a flight to credit for Tier Points, but be ineligible for Flying Club miles? For example, discount economy flights on Singapore book into classes that do not earn any miles in most programs. Even under KrisFlyer you usually get about 10% miles. However it's still a revenue economy fare, so do you get 1 tier point each segment (<2000 mi.)?