I actually wasn't referring to last minute changes. I'm thinking about the non-rev connecting itinerary where you may be in the air for several hours before the second segment of your flight, and what looked good on the ground is now full of more senior stand-bys. Of course, so much else can happen in the air, we shouldn't take anything for granted about the condition of the flight (specifically, I mean equipment changes, roll-overs from other flights, etc.). Just with FCFS, when you get on that first segment, you know where you stand in line.