Originally Posted by
mahasamatman
I don't think they use that criterion. The 747s and 767s debuted to/from FRA, and there's no competition there. They'll probably debut on the shortest possible routes for shakedowns.
My guess would be the highest yielding routes still served by 777s. Or you may see the 777 switched onto a 767 route (think ORD-LHR) and the 767 moved to the next highest-yielding route.